- Email: [email protected]
Design and implementation of a survey of people parking at curbside meters
003Rnl?1!83/0301?1-09%030010 Pergamon Prerc L!d
Socro-Emn. Ph. Sci. Vol. Ii, No. 3, pp 121-129, 1983 Printed m Great Britain
DESIGN AND IMPLEMENTATION OF A SURVEY OF PEOPLE PARKING AT CURBSIDE METERS F. F. ERNST and T. A. LAMBE School of Public Administration, University of Victoria, Victoria, B.C., Canada V8W 2Y2 (Receiued 24 ~epfe~ber 1982) Abstract-A practical procedure for planning and implementing a survey of the public to obtain relevant information for municipal decision-makers is illustrated with a study of motor vehicle parking at curbside meters. Principal components are: the definition of the problem; the development of a questionnaire in consultation with the politicians and their advisors; the design of a sampling plan to reflect the breadth of potential responses from the public, and the cost of obtaining interviews; the use of machine-readable forms to reduce the sources of error, and to facilitate the monitoring of interviewer ~~orman~e; and the application of statistical analysis, using standard computer programs to obtain quickly and accurately the results that are most meaningful to the ultimate decision-makers. The conclusions and recommendations from the survey may be applicable to other cities.
Municipal parking, like many other aspects of public transportation, often has recurring problems that require effective man~ement action. Typical decisions are when to change the time limits at curb meters, how much to raise hourly charging rates, and what level to set fines for violations. Motivation for action may come from complaints, observation of experience elsewhere, newspaper editorials, etc. These sources provide a limited and perhaps biased view of the problems, but they often cannot be ignored. A municipai government’s typical mechanism for responding to externally imposed problems is the formation of committees containing technical experts, politicians and appropriate representatives from special-interest groups. These committees not only receive initiatives from their members and the community, but also they generate new ideas while responding to such stimuli. In the city under study, a Parking Commission establishes the fees at five government-owned parking garages (called parkades), while a Traffic Sub-Committee recommends the rates and time limits for curbside meters. Thus an initial concensus is formed among the interested parties, and this preliminary policy passes onward to City Council where further modification may occur in response to the perception of a wider community interest. Although many factors affect the formulation of a response to a problem related to motor vehicle parking, knowledge of the behavior and attitudes of the parkers often is most important. It is the primary basis for predicting the impact on the system of any change in time limits, fees or fines. Without this knowledge, outside advisors, support staff and the politicians can only guess what will happen. What often is needed is a comprehansive survey of a relatively large and representative sample of parkers. The following sections of this paper present the basic steps for the design and implementation of a survey of public attitudes and behavior, illustrated with a study of people parking at curbside parking meters in the Central Business District of a community of 250,000 people. The study conforms to the traditional procedures for a research plan [ 11,including:
(1) Problem specification
(a) Previous reports and studies. fb) Public statements by politicians. (c) Newspaper articles. (d) Discussions with informed persons. (2) Design of research strategy (a) Develop a preliminary questionnaire on the basis of the foregoing sources. fb) Consult politicians, businessmen and traffic technicians to refine and confirm the measures they feel are important. (c) Modify questions and prepare for printing. (d) Test questionnaire on parkers. (e) Modify questions and test computer scanning capability. (f) Produce 4000 copies of the questionna~e. (3) Data gathering and processing (a) Select sample of meters to be surveyed. (b) Train interviewers. (c) Review initial questionnaire results, and re-train interviewers. (d) Supervise the interviewers and monitor the survey results. (4) Data analysis (a) Apply a standard computer program for statistical analysis, called Statistical Package for the Social Sciences (SPSS). (b) Test for internal stability of the survey results. (c) Detect significant characteristics of parker behavior and attitudes. (5) Conclusions, recommendatioits and report writing (a) Present preliminary findings to the Traffic Subcommittee, and to the Businessmen’s (b) Report to the City Engineer.
Association.
I’ROBLEM SPECIFICATION
A number of sources provide information on the values and perceptions of the principal people involved in the making of a decision within the context of muni121
122
F. F. ERNSTand T. A. LAMBE
cipal government. Personal interviews, excerpts from newspaper articles, and surveys of the literature give different perspectives of the problem. The composite picture not only helps to define the problem but also produces a first list of suitable questions for the survey of the public at large. A wide range of information was available for the parking study. A previous report on the impact of changes in parking garage fees had found that the demand for meter space was very high, that the practice of subsequently adding coins (remetering) was common, and that the occurrence of violation signs was frequent[2]. In addition, City Council had recently referred back (with consequent publicity) a Motion to double parking meter rates[3]. This topic then became a major issue in the municipal election that followed soon afterward. Typical views put forward by the campaigning incumbents included [4,5]: Mayor T.: Doubling the meter rates is not going to increase the number of parking spaces. It will only irritate people. New parkades are the only answer to additional parking, and there is a substantial amount of money in the off-street parking reserve fund to cover the construction. Ald. Bl.*: There is inequality between parking lot rates and meter rates. The city’s objective should be to maintain reasonably-priced parking downtown until more people live in the downtown area and support downtown merchants. (Asterisk denotes successful election.) Ald. Br.*: Meter rates should relate to parkade rates. Ald. Ca.*: They are the lowest rates of western cities. If the rates are increased, they may have to double due to the coins, so that the city can avoid having to ask for pennies in the meters. Ald. Co.*: Downtown parking has to be geared to the shopper, and the city should discourage all-day parking by offering alternatives through public transportation. Ald. McK.*: The city should increase turn-over at meters not by raising the rates but by reducing the time, and should build more parkades. Ald. Sr.: The parking meter rates should be raised modestly to account for inflation. Ald. W.: The City needs to build more parkades around the edge of the downtown core to serve all-day parkers and free-up existing parkades for use by shoppers. The challengers in the municipal election had other views [6]. The mayoralty challengers stated that: Former Mayor P.*: Increasing meter parking rates is shortsighted in the face of shopping center competition with downtown. He would introduce red warning tags to allow courtesy over-time parking (with a fine in the next round by the parking Commissionaire) to reduce current pressure on shoppers in the downtown area, and would explore the possibility of free (or nominal charge) parkade parking on Saturdays. Ald. McE.: All meters should be half-hour to encourage more turn-over by shoppers.
The challengers for the position of Alderman felt that: Ba.*: Raising the parking meter rates would only discourage people from shopping downtown. B. and M.: Instead of increasing parking meter rates, encourage downtown shopping by removing parking meters from the downtown entirely. Cl.*: The city could create more parking downtown by reducing the size of the parking stalls, since most people drive smaller cars. H.: Present rates are as low as anywhere else. K.: The rates for off-street and on-street parking should be the same. McD.: Shoppers should be encouraged to come downtown by such innovations as offering free Saturday parking in parkades. McL.: Parking is to help business. R.: Because people need an incentive to come downtown, it is stupid to raise the parking meter rates. Si.*: Look at options to encourage people to shop downtown, like allowing free parking on Saturdays. Add floors to some of the existing parkades. Interviews with the current and the former Chairman of the Traffic Sub-Committee, and with other interested persons revealed the following perspectives on the problem: Ald. Br.*: Bureaucrats hold great sway in policy-making; it is difficult for politicians to argue with their logic and technical expertise. She believes that the current policy is to have the meter fee bear some relationship to that of the parkades in order to encourage a high turn-over rate at the meters. The problem is that the Parking Commission, not City Council, controls the parkade rates. Consequently, the meter fees now are effectively cheaper than the parkades. Public complaints about the prospect of increased meter fees are relatively high, as the issue is something that is quite tangible. The other alternative is to make the time limits shorter. Although the meter rates are low, you cannot please everybody. Ald. McE.: Get rid of all-day parkers at curbs (remetering) by raising the meter fees to increase the space availability, which is the real problem. Increased price or reduced time limits will encourage a high turn-over rate, and therefore will make more efficient use of the parking spaces. Some people will always object, but let’s just do it and then people will (have to) get used to it. Director of the Chamber of Commerce: Parkers are treated like children, not like adults. It’s like liquorbureaucrats always think they know better. We must get away from this prohibition attitude. Parking should be free-make people more responsible, and they’ll act responsibly. We want downtown business-we must entice the parker. Former Chairman of the Transportation Committee of
Surveyof peopleparkingat curbsidemeters the Chamber of Commerce: Curbside parking downtown must be free, but with heavy enforcement of time limits. Don’t free parkades for shoppers; it will cut into the revenue. As for the argument that there should be a free spot available at all times, this simply means there aren’t enough shoppers. Curb spaces must be filled to capacity. Free parking downtown will do the job. The foregoing perspectives raised the following set of questions: (a) Turnover rates: How long do people stay at the meters? How long are the spaces vacant? (b) Violation rates: How often are meters without sufficient coins in them? (c) Remetering: How often do people return to add coins to extend their use of a space? (d) Meter time limits: Does the distribution of meters by time limit serve a useful purpose? (e) The parker: Where does he come from? Where does he go? How long does he stay? What does he do? (f) Price sensitivity: How would the parker react to a change in meter prices, and to a change in parkade prices? Does he value convenience more than price? DEVELOPING THEQUESTIONNAIRE
The set of questions established from the initial interviews and other sources forms the basis for a preliminary draft of the questionnaire, which then can be reviewed by the principal participants in the decisionmaking process. Thus these preliminary questions provide a means for communicating between the potential
123
users of the survey results, thereby establishing a rough consensus on the nature of the problem, and on the information needed for its resolution. In the parking meter study, these questions were represented by the first draft of the questionnaire as shown in Fig. 1. Further consultation with the politicians, support staff and businessmen interested in the problem resulted in the addition of questions to discover why parkers prefer meters, and how often they use them or parking garages; and to see whether parker behavior would change if meter prices were to double, or if parkades were free for the first hour. The interviews would require Comment Sheets to record where those parkers would go who suggested that they would no longer park at meters if rates were increased. The questions were then rearranged into a set that could precede an interview, and a subsequent set for the interview if time permitted, as shown in Fig. 2. In retrospect, the sex of the drivers and the passengers could have been added without burdening the interviewers, and thereby given further insight into the characteristics of the parkers. With the topics of the questions having been established, the next stage is to test the suitability of the wording from the standpoint of the interviewer and the interviewee. Limits have to be established for the time available for each interview, generally a minute or two. Ambiguities of wording have to be eliminated. The layout of the questionnaire has to be convenient not only for recording the standard replies, but also for the possibility of extensive comments. The latter often provide insights into the nature of the public’s perception of the
I I Response
I Question
I I I I I 1. I I
Range I
I Type
of Vehicle
Passenger.
2.
Type
of Parking
15. 30.
I I 3.
Time
In:
Hour
(01-12)
Minute
(00-59)
Hour
(01-12)
I
Truck.
I I
I 4.
Time
Out:
Last
Stop
I I I
Taxi.
(00-59)
Location
District
Corn.,
Other. 60.
Minute
Light
120-min.,
I
Exempt.
Code
I 5.
I 6.
Purpose
of Trip
I I I
Business,
Sot-Rec. -
Home LO Work. Walking
Destination
i 8.
~CHO~ Location
I 9.
No.
11. Meter
I 12. Meter i 13.
Street
of Passengers
Load.
Grid
District
I l 10. Their Trip Purpose
i
Shopping.
Code
(0 - 9) See Question
No.
No.
4 digits
in Violation
Yes.
No.
Fine
Yes,
No,
Unknown.
R metering
I I 14. Licence I
No.
3 letters
6
Fine
+ 3 digits
Fig. 1. First draft of questionnaire
Other.
I
I
F. F. ERNSTand T. A. LAMBE
124
,-
City and
xxxxx xxxxx
xxxxx
xxxxx
xxxxx xxxxx
xxxxx
xxxxx xxxxx
xxxxx
xxxxx xxxxx
xxxxx
xxxxx
xxxxx xxxxx xxxxx
xxxxx xxxxx Fig. 2. Seconddraft of questionnaire. problem, an important aspect in municipal decision-making. A corollary aspect of the test is the establishment of appropriate procedures for approaching the person to be interviewed, and for recording notes between interviews. The principal discovery from a pre-survey test with 60 persons in the parking study was that the responses tended to be ambiguous because the parkers did not have a clear idea of the purpose or intent of the question. To remedy the situation, Likert scales were added to facilitate the questioning and to measure the strength of the response. In particular, Question 14 of Fig. 2 was reworded to say:
The same set of responses were used for the following new question that was inserted next:
“Doubling the meter rates will affect me. I would have parked elsewhere or taken the bus”.
All of these changes were tested before the survey began. Finally, the print size and spacing were adjusted to make the form more legible and convenient for the interviewer, and to provide space for a second reason for prefering meters (Question 13 of Fig. 2).
The coded responses were: no answer, strongly disagree, disagree, neutral, agree, strongly agree.
“Doubling meter rates will make it easier to find a free spot”, and for the following revised wording of Question 17 to reveal what the parker would have done specifically for this particular trip: “If parking garages liad offered me free parking for the first hour, I would have parked there today.”
Surveyof peopleparkingat curbsidemeters The pre-survey test also found that approaching the parker as he returned to his vehicle for departure was preferable to conducting the interview as he was inserting coins into the meter on arrival. A test of each found that parkers tended to have less time and viewed the interviewer with greater suspicion when the interview was conducted at the transaction’s start. Thus bias in the responses to attitudinal questions was reduced by interviewing the parker when he returned to his vehicle. Furthermore, parker behavior would not be affected by the presence of the interviewer if this person remained inconspicuous when recording arrival times. When a survey requires the collection of a large volume of data, some type of machine-readable form becomes desirable in order to reduce survey costs, and more importantly to avoid the chance of error during subsequent analysis. Because the development of a suitable form takes considerable time and experimentation to satisfy the machine reading requirements, a good approach is to use an existing form, and superimpose the questions onto this form by photographic means. The benefits of a readily usable form outweigh the possible problem of limited space and flexibility. As shown in Fig. 2, the parking survey was printed onto a standard optical scanning sheet customarily used for recording answers to multiple-choice examination questions. It had 25 rows with provision for recording four decimal digits per row. By suitable design, only the two digits on the right side were needed so that the left-hand half of the sheet could receive the (photographed) questions, and provide space for the answers and for comments. The light green color of the form did not interfere with the legibility of the over-printed questions in black. Although several trial runs were required to test the print alignments with the scanner equipment, no persistent problems occurred. The total cost for materials, graphic design and printing was $200 plus $0.05 per sheet for 4000 copies. The interviewers had the responsibility of transcribing the standard answers onto the appropriate mark-sense region on the right side of the questionnaire form, a task that they usually were able to accomplish during slack periods between the arrival of people to interview. Each sheet had an identification number that represented the street, meter number, time limit, day of week, and the interviewer. After the pre-survey test of the questionnaire, the resulting data was again run through the scanning equipment. Interviewer coding was superb; there were no errors. The concept for data collection, coding and submission appeared sound. lNTRRVlRWING
Management is the key concept at this stage of the project. Survey areas must be established, personnel selected, job training provided, performance monitored and remuneration paid. Each link in the chain is vital for successful results. Stratitied random sampling is the basic concept for reducing the chance of bias and error. The principal idea is to divide the universe of possible interviewing opportunities into homogeneous groups that have non-overlapping characteristics, and select at random individuals for interviewing within each group. Neither the size of the group nor the fraction interviewed has to be constant. In general, the groupings can be determined by dividing the universe according to readily observable
125
characteristics that a priori appear to imply distinctive characteristics. With several such divisions, the number of sub-groups increases exponentially. To minimize overall error, the sample from each group should be roughly proportional to the size of the group. However, small groups should have a slightly higher density of survey to increase their percent accuracy for diagnostic purposes. Overall results for the universe then can be obtained by taking the weighted sum of the sample results. The total number of people interviewed theoretically should reflect a balance between the cost of additional data and its potential value. For the parking survey, the universe of potential interviews was the Central Business District during a typical week in Spring. This was sub-divided by three factors: meter time-limit, city block and the day of the week. The first factor delineated four sets of meters: 116 with l/4-hr time limits, 183 with l/2-hr limits, 906 with I-hr, and 381 with 2hr limits, or 1586meters in total. The second factor identified roughly 80 city blocks, while the third produced the five weekdays from Monday to Friday. For each meter in the survey, it was necessary to observe parking behavior from 8 : 00 a.m. to 6 : 00 p.m. in order to give essentially complete information on the characteristics of people parking during the period of peak demand from 9: 30 a.m. to 4: 00 p.m. Experience during the pre-survey test period with the questionnaire established that a single person could observe all people parking at approximately four adjoining l/4-hr meters, five l/2-hr meters, seven one-hour meters or ten 2-hr meters, but could interview only 70% of these people due to the occurrence of multiple demands. Therefore economy suggested that adjacent meters be selected, but not necessarily those with the same time limits. Furthermore, the budget constraint dictated that no meter be surveyed more than once. Thus, the overall sample size was set at 30 l/4-hr, 56 l/2-hr, 161 1-hr and 52 2-hr meters, comprising 19 percent of the total meters. Within these constraints, appropriate groupings of meters were selected from alternate city blocks in a random pattern spatially and temporally throughout the Central Business District during March and April, 1982. The hiring of suitable interviewers poses a serious challenge. These people must be trustworthy, sufficiently intelligent, inter-personally adept, well-motivated and available. Personal recommendations from known colleagues is one source. Advertisements in appropriate places is another. The size of this group must be large enough to accommodate a few absences due to illness or other temporary commitments, yet not any larger than necessary to do the job in the time available. Otherwise the cost of training and supervision rises unnecessarily. In the parking study, six individuals were hired through ads and personal contacts, of whom four were selected to form a continuously working crew, while the other two remained as backup for emergencies. This approach worked very well. Each person was provided with a coding manual that gave detailed instruction on how to translate the data to machine-readable form. Special information was provided for some of the difhcult questions, such as Nos. 13 and 14 in Fig. 2. The manual was adjusted in the first week of trial interviews to correct ambiguities, missing instructions and the like. Interviewers were also expected to submit Comment Sheets that highlighted all interesting developments observed during the day. By the
126
F. F. ERNST and T. A. LAMBE
start of the survey, the interviewers were very familiar, with the procedure. Since an 8: 00 a.m. to 6:00 p.m. coverage was desired, two interviewers worked from 8: 00 to 1: 00 p.m., and the. other two from 1:00 to 6:00 p.m. Because the meter groups were widely distributed, these people could not assist each other during busy periods, nor spell off each other with time for a break. Interviewers were paid for 6.5 hr to cover extra time for coding, especially needed following a hectic day at centrally-located l/4-hr parking meters, and to compensate for the absence of coffee breaks, etc., during the five-hour interviewing period. Machine-readable interview forms greatly facilitate the monitoring of job performance. At the end of each day, the collected forms can be listed on a computer print-out sheet for a quick visual scan to detect obvious discrepancies (e.g. missing meter numbers, misalignments, etc.) and such forms can then be returned to the appropriate interviewer for correction. Subsequent statistical analysis with standardized computer programs provide a further level of checking. However these checking procedures are not completely safe from fraud, in that a skillful interviewer can cover-up absenteeism by creating fake data that may not be detectable. Consequently, unannounced spot checking is a necessity for adequate supervision. In the parking meter study, the error rate detected by a visual scan was 50 per 1000questionnaires, and a further* 5 per 1000 were detected by the subsequent statistical analysis. All errors were due to the interviewers, as no problems whatsoever arose from the scanning equip- . ment. DATAANALYSIS AND RESULTS Although the sampling procedure establishes external validity, the assembled data should be subjected to a thorough analysis to check for internal validity[7]. This process includes consideration of the influence of temporal trends in interviewee behavior, of the impact of the interviewer’s presence on the foregoing behavior, and of the differences that may arise in the standards of procedure and interpretation used by the different interviewers (Instrumentation and Testing effects.) Following. consideration of these three aspects of internal validity, the data can receive a thorough statistical analysis to establish the presence of substantive relationships, the, principal procedure being the chi-square test. In terms of the parking meter study, internal validity was supported by the observation that no trends were detected across the two-months of the survey, that the parkers did not see the interviewer until they were on the point of driving away from the meters, that the number of observations collected on each day of the week was approximately equal, and that no significant difference in results could be detected between the interviewers.‘ Extensive pre-survey training and testing provided an equal standard for all interviewers, as it was important that they ask the questions correctly, and code the. responses in a similar manner. The loss of interviews as a result of multiple departures, or departures after 6:00 p.m., did not introduce bias. The miss rate was roughly the same (29-33%) for all meter time limits. Although greater at two high activity 15-min. meter clusters (near the Post Office and the Liquor Store), the number missed at these two locations was not likely to include users with different attitudes from those at other 15-min. meters. Multiple departures.
occurred randomly throughout the period; they were not clustered in the lunch hour, for example. The number of parkers who refused to be interviewed was small (about 40 out of 2500), and even if they were dramatically different from other respondents, their contribution would not have had a significant impact on the results. These non-respondents were typically busy executives, or people who had been interviewed previously. The data on parker behavior and parker attitude permitted the testing of a number of the hypotheses or beliefs commonly held by the people who formulate parking policy. Table 1 briefly describes the purpose of each question and illustrates the nature of the experiment. The primary hypotheses were: (1) Shoppers are the major user of meter space. (2) Demand for meters is very high. (3) Time violation and remetering are common occurrences. (4) Parkers value the convenience of meter locations. (5) Meter price is a major factor influencing people to come downtown. Table 2 shows that the purpose of the trip differs significantly according to the meter chosen. Shoppers provide the greatest demand for 15-min. meters, while business and social-recreational trips dominate the 120min. meters. The trends underlying these changes progress smoothly as the meter time limit increases, in part reflecting fewer shopping opportunities near 2-hr meters, and in part reflecting the influence of trip purpose on desired parking duration. With a total of 2581 interviews, the chance of these trends occurring due to random sampling error is negligible, the SPSS computer program giving a chi-square value of 240 for this cross-tabulation with 15 degrees of freedom. The combined figures, weighted by the number of meters in the city core, confirmed the hypothesis that shoppers provide the primary demand for meters. The length of time a person chooses to stay at a meter quite naturally depends on the trip purpose. It also depends on the time limit for the meter! As shown in Table 2, the median time at 15-min. meters ranges from 8 min. for Loading, to 31 minutes for Job related trips. For 120-min. meters on the other hand, loading seldom occurs, and the median time for Job trips is 116min. Undoubtably, the relative availability of the different type of meters in the preferred locations has a bearing on which space a driver chooses, all of these people arriving between 8:00 a.m. and 6:00 p.m. However, given that a person does select a curb meter, the parking duration is more likely to exceed the median for the trip purpose if the meter time limit is 120min. rather than 15 min. The distribution of occupancy time provides one measure of overall demand. Table 3 reveals that onethird of the people stay longer than the limit at I5 and 30-min. meters, 20% stay longer than the limit at 60, and only 7% stay longer than the limit at 120-min. meters during the period between 9: 30 a.m. and 4:00 p.m. For the day as a whole, the percentages exceeding the time limits are 35, 39, 24 and 20 respectively, where the numbers of parkers observed were 643,881, 1688and 247 respectively, for a total of 3459 vehicles. Thus the time limit is exceeded more often at the shorter-term meters. The distribution of vacant periods between successive users of a space provides another measure of demand. As shown in Table 3, one vehicle immediately follows another in 28% of the departures. The average time vacant tends to increase with the time limit of the meter,
Survey of people par&g at curbside meters
127
Table 1. Relationship of questions to issues
the
shoppera “re
primarp
m8tet weft demand for
meterparkin@
is very high vieXaCiono.
vioXatioas
vhy parkers
prefer
parkera value the convenience
I of meter locations I I 1 parker6are eensitive tO price: 1 f the major factor influencing
meters attitude
of parker
t* meterrate increases,
and reaeteriag
free
perkade parking. tlJrlWNW/priCe telafionships origin-destination
fat B subsequent
and frequency
I
I
Table:2, Trip
purpose
of traffic
study
flow
I
and median parking duration .6
c
I
PWpolL of
Trip
I I
I
Metar Time Limit
I
t t t IFHinutaE
I’ i
fD-SiIiautcs
40+4imtra
lZ#-?tinUtC*
OV?rtll t
t I
I
I I
I I
7.
Win.
1
X
Uin.
%
Min.
Z
nin.
X
Min. I
20
52
24
17
35
46
22
70
9
57
12
16
I8
2%
22
2g
28
30
22
28
4
21
11
33
9
32
34
57
15
52
6
31
6
20
a
53
1s
116
9
76
Load
I I 1
4
8
5
9
-
=
3
13
Other
t
3
7
4
13
6
17
5
Ib
Shop
t I Scx?Rec i 1
Business
Job
414 5
I7
I I t I I 1 I
I I
I I t i
OVeiall Bample
/ c
i i I
108 487
10
fOO bbl
22
100 1262
28
loa 165
51
loo
3l
1’ I *
F. F. ERNSTand T. A. LAMBE
128
Table 3. Percent distribution of occupancy and vacancy periods
,
W-
I
I
I Meter
1 Duration
Time Limit
(Minutes) 15-Minutes
occ.
>
VK.
30-Minutes
60-Minutes
occ.
occ.
Vat .
Vat.
IZO-Minutes
occ.
Overrll
Vat.
occ.
Vat.
100
83
100
76
100
74
100
60
100
72
> 5
74
32
07
32
91
28
92
36
90
31
>
10
48
18
71
20
75
19
81
27
74
21
> 15
31
11
60
14
65
14
73
22
64
16
> 30
13
5
34
7
42
9
50
13
41
9
0
I > 60
I
4
2
11
3
20
3
33
3
21
3
i I
i I
2
1
3
0
4
1
7
1
4
1
Avg. Min. i
14
43
10.9
33
I
,120
I Variance
I I I c
Sample
8.3
26
8.7
33
9.4
396
360
483
250
440
524
1025
135
but this may be due to sampling variability, the Fstatistic being 0.2 with 3 and 2120 degrees of freedom respectively. For the overall region, the vacancy rate was 20%, roughly triple that found in 1979 for a smaller sample in a central and localized area during the same period of peak demand [2]. Record selection, another feature of the SPSS computer program, enables special subsets of interviews to be assembled into a separate group for analysis. Thus in the parking study, those people having a violation sign showing (due to insufficient money in the meter) could be analyzed separately to detect the incidence of fines. The results showed that there was a one percent chance of receiving a ticket for a fine with every 5 min. that the meter showed the violation sign during the period from 8:OOa.m. to 6:00 p.m. With a $3.00 fine costing 15 times the hourly fee for the meter, the parker could expect to pay on average double the regular rate by taking a chance on not having sufficient coins in the meter. The foregoing observations do not include the 8% of all parkers who remetered in order to stay longer than the time limit without the violation sign showing, of whom a sixth returned at least twice to add coins. None of these people received a fine. Detection of remetering by chalking tires, or recording licence numbers, is a time consuming task for the Commissionaires. The incidence of remetering was significantly lower (2%) at 15-min. meters, as might be expected from
9.6
*
in contrast to 43% at 30 and 60-min. meters. This result is statistically significant, with a chi-square value of 33 on 3 degrees of freedom, and may be due to the lower relative convenience of garages, which were some distance away from the 2-hr meters. All respondents tended to qualify their interest in free parking with the requirement that the parkade had to be ‘close’ to their destination. It was fairly clear from the comments on the Interview Sheets that convenient access and proximity to their destination was more important than economic factors to most parkers. This is not a surprising result in this particular study, as the curbside meters offered both aspects, meter rates not having changed during the inflationary eight years since 1974. One-quarter of all people said that they would no longer use a meter if the rates were doubled, and most of these would park elsewhere. This result was independent of trip purpose, remetering and meter time limit, except for 15-min. meters where only 1% would be affected. However, of specific concern to the businessman was the potential impact of a doubling of meter charge rates on the number of people shopping downtown, and the potential offsetting effect of having free parking in municipal parking garages during the first hour of use (instead of the current nominal fee of $0.25). While four percent of all parkers said that they would shop or do their business elsewhere if meter rates were doubled, 75% of these people said that they would park in a garage if it was free for the first hour. Hence a negligible one percent of all parkers indicated that they would not come to town if meter rates were doubled while the garages were free for the first hour. Whether parkers will do on average what they say they will do is of course a matter for conjecture, but the attitude expressed by the parkers is an important consideration for City Council. In summary, the first five hypotheses of Table 1 were supported by the survey results, but the (second) one
129
Survey of people parking at curbside meters concerning high demand for meter space appeared to be relevant only to the most central area of the business district. CONCLUSIONSAND RECOMMENDATIONS
The results obtained from a well-designed survey should reduce uncertainty about the major aspects of the
problem facing the decision-makers. Thus these people along with their advisors must be consulted while the questionnaire is being developed. Furthermore, the use of a preliminary list of questions abstracted from previously available material helps to give a focus and coherence to the consultative process. Because many people along the chain of communication participate in the planning of the questionnaire, the results of the survey receive comprehending and interested attention, which facilitate transmission of the information within the relevant parts of the municipal decision-making system. In the case of the parking study, the results of the survey were presented in the form of a recommendation with supporting data. The principal recommendation was that parking meter rates should be doubled in the central region, while the nearby parkades would be free for the tirst hour of a parker’s use. This combination would make more space available at the curb meters for those who put high value on convenience, while providing inexpensive parking for those who are primarily concerned about cost. The survey had indicated that virtually everyone favoured most highly one of these two aspects, convenience and economy, but that hardly anyone would balk at going to the Central Business District because they did not get both together. Because the public clearly perceives the relative convenience and cost of each parking alternative, the report recommended a policy of maintaining a balance between these aspects for all such services offered by the municipality. In particular, the fee for using a curb meter should reflect the basic value the public puts onto this most convenient of parking locations. Such a fee should be at least as high as those at nearby commercial parking lots so that space always is available because excessive demand is avoided, fine tuning of demand being achieved by the use of shorter or longer time limits in special locations. Market rates also will tend to reduce the incentive for remetering. Furthermore, to encourage curbside parkers to put sufficient money into the meter when thev park. and not to over-stav the time limit. the
combination of fines and enforcement should be kept at an appropriately higher level than the rate charged by the meter. Parking garages can draw shopping and business trips to town by charging a very low rate for the short-term, while disuading excess demand from commuters by charging above-market rates for all-day parking. As demand for short-term parking grows, the City can construct more garages, using the funds from excess revenue over expense at parking meters. Demand for longterm parking space can be satisfied at commercial rates by private enterprise. Discussions arising during the presentation of the preliminary results to the Traffic Sub-Committee and to the Downtown Businessmen’s Association indicated that the division of authority between the foregoing Committee and the Parking Commission would continue to impede effective co-ordination of the planning for meters, lots and parkades. Consequently, to facilitate the implementation of changes in parking policy, City Council has approved a Bylaw that will restructure the committee system so that all relevant decisions will come under a single committee, instead of the current division between the Traffic Sub-Committee and the Parking Commission. Thus it can be expected that in the course of time, the foregoing recommendations will be addressed in the light of the survey results and the other considerations that normally impinge upon municipal decision-making. REFERENCES
I. T. H. Poister, Public Program Analysis, pp. 27-28. University
Park Press, Baltimore, Maryland (1978). 2. T. A. Lambe and C. D. Wild, Formulation and implementation of a pricing policy for municipal parking. Socio-&on. Plan. Sci. 14, 25-32 (1980). 3. CHEK Television, Interview of Ald. G. Brewin, Chairman of Traffic Sub-Committee, City of Victoria, 15 Oct. 1981. 4. C. Fornssler, Mayor McElroy, Mayor Pollen or Mayor Tindall?. Monday Publications Ltd., Victoria, B.C., Monday Magazine 7(12), 10-13 (6 Nov. 1981). 5. C. Fornssler, If elected I promise. Monday Publications Ltd., Victoria, B.C., Monday Magazine 7(13), 8-13, (13 Nov. 1981). 6. C. Fornssler, Taking aim at the incumbents. Monday Publications Ltd., Victoria, B.C., Monday Magazine 7(14), 10-21 (20 Nov. 1981). 7. T. H. Poister, J. McDavid and A. Magoun, Appl. Program Evaluation in Local Government, pp. 13-29. Lexington Books, Pennsylvania State University, Penn. (1971).
Socro-Emn. Ph. Sci. Vol. Ii, No. 3, pp 121-129, 1983 Printed m Great Britain
DESIGN AND IMPLEMENTATION OF A SURVEY OF PEOPLE PARKING AT CURBSIDE METERS F. F. ERNST and T. A. LAMBE School of Public Administration, University of Victoria, Victoria, B.C., Canada V8W 2Y2 (Receiued 24 ~epfe~ber 1982) Abstract-A practical procedure for planning and implementing a survey of the public to obtain relevant information for municipal decision-makers is illustrated with a study of motor vehicle parking at curbside meters. Principal components are: the definition of the problem; the development of a questionnaire in consultation with the politicians and their advisors; the design of a sampling plan to reflect the breadth of potential responses from the public, and the cost of obtaining interviews; the use of machine-readable forms to reduce the sources of error, and to facilitate the monitoring of interviewer ~~orman~e; and the application of statistical analysis, using standard computer programs to obtain quickly and accurately the results that are most meaningful to the ultimate decision-makers. The conclusions and recommendations from the survey may be applicable to other cities.
Municipal parking, like many other aspects of public transportation, often has recurring problems that require effective man~ement action. Typical decisions are when to change the time limits at curb meters, how much to raise hourly charging rates, and what level to set fines for violations. Motivation for action may come from complaints, observation of experience elsewhere, newspaper editorials, etc. These sources provide a limited and perhaps biased view of the problems, but they often cannot be ignored. A municipai government’s typical mechanism for responding to externally imposed problems is the formation of committees containing technical experts, politicians and appropriate representatives from special-interest groups. These committees not only receive initiatives from their members and the community, but also they generate new ideas while responding to such stimuli. In the city under study, a Parking Commission establishes the fees at five government-owned parking garages (called parkades), while a Traffic Sub-Committee recommends the rates and time limits for curbside meters. Thus an initial concensus is formed among the interested parties, and this preliminary policy passes onward to City Council where further modification may occur in response to the perception of a wider community interest. Although many factors affect the formulation of a response to a problem related to motor vehicle parking, knowledge of the behavior and attitudes of the parkers often is most important. It is the primary basis for predicting the impact on the system of any change in time limits, fees or fines. Without this knowledge, outside advisors, support staff and the politicians can only guess what will happen. What often is needed is a comprehansive survey of a relatively large and representative sample of parkers. The following sections of this paper present the basic steps for the design and implementation of a survey of public attitudes and behavior, illustrated with a study of people parking at curbside parking meters in the Central Business District of a community of 250,000 people. The study conforms to the traditional procedures for a research plan [ 11,including:
(1) Problem specification
(a) Previous reports and studies. fb) Public statements by politicians. (c) Newspaper articles. (d) Discussions with informed persons. (2) Design of research strategy (a) Develop a preliminary questionnaire on the basis of the foregoing sources. fb) Consult politicians, businessmen and traffic technicians to refine and confirm the measures they feel are important. (c) Modify questions and prepare for printing. (d) Test questionnaire on parkers. (e) Modify questions and test computer scanning capability. (f) Produce 4000 copies of the questionna~e. (3) Data gathering and processing (a) Select sample of meters to be surveyed. (b) Train interviewers. (c) Review initial questionnaire results, and re-train interviewers. (d) Supervise the interviewers and monitor the survey results. (4) Data analysis (a) Apply a standard computer program for statistical analysis, called Statistical Package for the Social Sciences (SPSS). (b) Test for internal stability of the survey results. (c) Detect significant characteristics of parker behavior and attitudes. (5) Conclusions, recommendatioits and report writing (a) Present preliminary findings to the Traffic Subcommittee, and to the Businessmen’s (b) Report to the City Engineer.
Association.
I’ROBLEM SPECIFICATION
A number of sources provide information on the values and perceptions of the principal people involved in the making of a decision within the context of muni121
122
F. F. ERNSTand T. A. LAMBE
cipal government. Personal interviews, excerpts from newspaper articles, and surveys of the literature give different perspectives of the problem. The composite picture not only helps to define the problem but also produces a first list of suitable questions for the survey of the public at large. A wide range of information was available for the parking study. A previous report on the impact of changes in parking garage fees had found that the demand for meter space was very high, that the practice of subsequently adding coins (remetering) was common, and that the occurrence of violation signs was frequent[2]. In addition, City Council had recently referred back (with consequent publicity) a Motion to double parking meter rates[3]. This topic then became a major issue in the municipal election that followed soon afterward. Typical views put forward by the campaigning incumbents included [4,5]: Mayor T.: Doubling the meter rates is not going to increase the number of parking spaces. It will only irritate people. New parkades are the only answer to additional parking, and there is a substantial amount of money in the off-street parking reserve fund to cover the construction. Ald. Bl.*: There is inequality between parking lot rates and meter rates. The city’s objective should be to maintain reasonably-priced parking downtown until more people live in the downtown area and support downtown merchants. (Asterisk denotes successful election.) Ald. Br.*: Meter rates should relate to parkade rates. Ald. Ca.*: They are the lowest rates of western cities. If the rates are increased, they may have to double due to the coins, so that the city can avoid having to ask for pennies in the meters. Ald. Co.*: Downtown parking has to be geared to the shopper, and the city should discourage all-day parking by offering alternatives through public transportation. Ald. McK.*: The city should increase turn-over at meters not by raising the rates but by reducing the time, and should build more parkades. Ald. Sr.: The parking meter rates should be raised modestly to account for inflation. Ald. W.: The City needs to build more parkades around the edge of the downtown core to serve all-day parkers and free-up existing parkades for use by shoppers. The challengers in the municipal election had other views [6]. The mayoralty challengers stated that: Former Mayor P.*: Increasing meter parking rates is shortsighted in the face of shopping center competition with downtown. He would introduce red warning tags to allow courtesy over-time parking (with a fine in the next round by the parking Commissionaire) to reduce current pressure on shoppers in the downtown area, and would explore the possibility of free (or nominal charge) parkade parking on Saturdays. Ald. McE.: All meters should be half-hour to encourage more turn-over by shoppers.
The challengers for the position of Alderman felt that: Ba.*: Raising the parking meter rates would only discourage people from shopping downtown. B. and M.: Instead of increasing parking meter rates, encourage downtown shopping by removing parking meters from the downtown entirely. Cl.*: The city could create more parking downtown by reducing the size of the parking stalls, since most people drive smaller cars. H.: Present rates are as low as anywhere else. K.: The rates for off-street and on-street parking should be the same. McD.: Shoppers should be encouraged to come downtown by such innovations as offering free Saturday parking in parkades. McL.: Parking is to help business. R.: Because people need an incentive to come downtown, it is stupid to raise the parking meter rates. Si.*: Look at options to encourage people to shop downtown, like allowing free parking on Saturdays. Add floors to some of the existing parkades. Interviews with the current and the former Chairman of the Traffic Sub-Committee, and with other interested persons revealed the following perspectives on the problem: Ald. Br.*: Bureaucrats hold great sway in policy-making; it is difficult for politicians to argue with their logic and technical expertise. She believes that the current policy is to have the meter fee bear some relationship to that of the parkades in order to encourage a high turn-over rate at the meters. The problem is that the Parking Commission, not City Council, controls the parkade rates. Consequently, the meter fees now are effectively cheaper than the parkades. Public complaints about the prospect of increased meter fees are relatively high, as the issue is something that is quite tangible. The other alternative is to make the time limits shorter. Although the meter rates are low, you cannot please everybody. Ald. McE.: Get rid of all-day parkers at curbs (remetering) by raising the meter fees to increase the space availability, which is the real problem. Increased price or reduced time limits will encourage a high turn-over rate, and therefore will make more efficient use of the parking spaces. Some people will always object, but let’s just do it and then people will (have to) get used to it. Director of the Chamber of Commerce: Parkers are treated like children, not like adults. It’s like liquorbureaucrats always think they know better. We must get away from this prohibition attitude. Parking should be free-make people more responsible, and they’ll act responsibly. We want downtown business-we must entice the parker. Former Chairman of the Transportation Committee of
Surveyof peopleparkingat curbsidemeters the Chamber of Commerce: Curbside parking downtown must be free, but with heavy enforcement of time limits. Don’t free parkades for shoppers; it will cut into the revenue. As for the argument that there should be a free spot available at all times, this simply means there aren’t enough shoppers. Curb spaces must be filled to capacity. Free parking downtown will do the job. The foregoing perspectives raised the following set of questions: (a) Turnover rates: How long do people stay at the meters? How long are the spaces vacant? (b) Violation rates: How often are meters without sufficient coins in them? (c) Remetering: How often do people return to add coins to extend their use of a space? (d) Meter time limits: Does the distribution of meters by time limit serve a useful purpose? (e) The parker: Where does he come from? Where does he go? How long does he stay? What does he do? (f) Price sensitivity: How would the parker react to a change in meter prices, and to a change in parkade prices? Does he value convenience more than price? DEVELOPING THEQUESTIONNAIRE
The set of questions established from the initial interviews and other sources forms the basis for a preliminary draft of the questionnaire, which then can be reviewed by the principal participants in the decisionmaking process. Thus these preliminary questions provide a means for communicating between the potential
123
users of the survey results, thereby establishing a rough consensus on the nature of the problem, and on the information needed for its resolution. In the parking meter study, these questions were represented by the first draft of the questionnaire as shown in Fig. 1. Further consultation with the politicians, support staff and businessmen interested in the problem resulted in the addition of questions to discover why parkers prefer meters, and how often they use them or parking garages; and to see whether parker behavior would change if meter prices were to double, or if parkades were free for the first hour. The interviews would require Comment Sheets to record where those parkers would go who suggested that they would no longer park at meters if rates were increased. The questions were then rearranged into a set that could precede an interview, and a subsequent set for the interview if time permitted, as shown in Fig. 2. In retrospect, the sex of the drivers and the passengers could have been added without burdening the interviewers, and thereby given further insight into the characteristics of the parkers. With the topics of the questions having been established, the next stage is to test the suitability of the wording from the standpoint of the interviewer and the interviewee. Limits have to be established for the time available for each interview, generally a minute or two. Ambiguities of wording have to be eliminated. The layout of the questionnaire has to be convenient not only for recording the standard replies, but also for the possibility of extensive comments. The latter often provide insights into the nature of the public’s perception of the
I I Response
I Question
I I I I I 1. I I
Range I
I Type
of Vehicle
Passenger.
2.
Type
of Parking
15. 30.
I I 3.
Time
In:
Hour
(01-12)
Minute
(00-59)
Hour
(01-12)
I
Truck.
I I
I 4.
Time
Out:
Last
Stop
I I I
Taxi.
(00-59)
Location
District
Corn.,
Other. 60.
Minute
Light
120-min.,
I
Exempt.
Code
I 5.
I 6.
Purpose
of Trip
I I I
Business,
Sot-Rec. -
Home LO Work. Walking
Destination
i 8.
~CHO~ Location
I 9.
No.
11. Meter
I 12. Meter i 13.
Street
of Passengers
Load.
Grid
District
I l 10. Their Trip Purpose
i
Shopping.
Code
(0 - 9) See Question
No.
No.
4 digits
in Violation
Yes.
No.
Fine
Yes,
No,
Unknown.
R metering
I I 14. Licence I
No.
3 letters
6
Fine
+ 3 digits
Fig. 1. First draft of questionnaire
Other.
I
I
F. F. ERNSTand T. A. LAMBE
124
,-
City and
xxxxx xxxxx
xxxxx
xxxxx
xxxxx xxxxx
xxxxx
xxxxx xxxxx
xxxxx
xxxxx xxxxx
xxxxx
xxxxx
xxxxx xxxxx xxxxx
xxxxx xxxxx Fig. 2. Seconddraft of questionnaire. problem, an important aspect in municipal decision-making. A corollary aspect of the test is the establishment of appropriate procedures for approaching the person to be interviewed, and for recording notes between interviews. The principal discovery from a pre-survey test with 60 persons in the parking study was that the responses tended to be ambiguous because the parkers did not have a clear idea of the purpose or intent of the question. To remedy the situation, Likert scales were added to facilitate the questioning and to measure the strength of the response. In particular, Question 14 of Fig. 2 was reworded to say:
The same set of responses were used for the following new question that was inserted next:
“Doubling the meter rates will affect me. I would have parked elsewhere or taken the bus”.
All of these changes were tested before the survey began. Finally, the print size and spacing were adjusted to make the form more legible and convenient for the interviewer, and to provide space for a second reason for prefering meters (Question 13 of Fig. 2).
The coded responses were: no answer, strongly disagree, disagree, neutral, agree, strongly agree.
“Doubling meter rates will make it easier to find a free spot”, and for the following revised wording of Question 17 to reveal what the parker would have done specifically for this particular trip: “If parking garages liad offered me free parking for the first hour, I would have parked there today.”
Surveyof peopleparkingat curbsidemeters The pre-survey test also found that approaching the parker as he returned to his vehicle for departure was preferable to conducting the interview as he was inserting coins into the meter on arrival. A test of each found that parkers tended to have less time and viewed the interviewer with greater suspicion when the interview was conducted at the transaction’s start. Thus bias in the responses to attitudinal questions was reduced by interviewing the parker when he returned to his vehicle. Furthermore, parker behavior would not be affected by the presence of the interviewer if this person remained inconspicuous when recording arrival times. When a survey requires the collection of a large volume of data, some type of machine-readable form becomes desirable in order to reduce survey costs, and more importantly to avoid the chance of error during subsequent analysis. Because the development of a suitable form takes considerable time and experimentation to satisfy the machine reading requirements, a good approach is to use an existing form, and superimpose the questions onto this form by photographic means. The benefits of a readily usable form outweigh the possible problem of limited space and flexibility. As shown in Fig. 2, the parking survey was printed onto a standard optical scanning sheet customarily used for recording answers to multiple-choice examination questions. It had 25 rows with provision for recording four decimal digits per row. By suitable design, only the two digits on the right side were needed so that the left-hand half of the sheet could receive the (photographed) questions, and provide space for the answers and for comments. The light green color of the form did not interfere with the legibility of the over-printed questions in black. Although several trial runs were required to test the print alignments with the scanner equipment, no persistent problems occurred. The total cost for materials, graphic design and printing was $200 plus $0.05 per sheet for 4000 copies. The interviewers had the responsibility of transcribing the standard answers onto the appropriate mark-sense region on the right side of the questionnaire form, a task that they usually were able to accomplish during slack periods between the arrival of people to interview. Each sheet had an identification number that represented the street, meter number, time limit, day of week, and the interviewer. After the pre-survey test of the questionnaire, the resulting data was again run through the scanning equipment. Interviewer coding was superb; there were no errors. The concept for data collection, coding and submission appeared sound. lNTRRVlRWING
Management is the key concept at this stage of the project. Survey areas must be established, personnel selected, job training provided, performance monitored and remuneration paid. Each link in the chain is vital for successful results. Stratitied random sampling is the basic concept for reducing the chance of bias and error. The principal idea is to divide the universe of possible interviewing opportunities into homogeneous groups that have non-overlapping characteristics, and select at random individuals for interviewing within each group. Neither the size of the group nor the fraction interviewed has to be constant. In general, the groupings can be determined by dividing the universe according to readily observable
125
characteristics that a priori appear to imply distinctive characteristics. With several such divisions, the number of sub-groups increases exponentially. To minimize overall error, the sample from each group should be roughly proportional to the size of the group. However, small groups should have a slightly higher density of survey to increase their percent accuracy for diagnostic purposes. Overall results for the universe then can be obtained by taking the weighted sum of the sample results. The total number of people interviewed theoretically should reflect a balance between the cost of additional data and its potential value. For the parking survey, the universe of potential interviews was the Central Business District during a typical week in Spring. This was sub-divided by three factors: meter time-limit, city block and the day of the week. The first factor delineated four sets of meters: 116 with l/4-hr time limits, 183 with l/2-hr limits, 906 with I-hr, and 381 with 2hr limits, or 1586meters in total. The second factor identified roughly 80 city blocks, while the third produced the five weekdays from Monday to Friday. For each meter in the survey, it was necessary to observe parking behavior from 8 : 00 a.m. to 6 : 00 p.m. in order to give essentially complete information on the characteristics of people parking during the period of peak demand from 9: 30 a.m. to 4: 00 p.m. Experience during the pre-survey test period with the questionnaire established that a single person could observe all people parking at approximately four adjoining l/4-hr meters, five l/2-hr meters, seven one-hour meters or ten 2-hr meters, but could interview only 70% of these people due to the occurrence of multiple demands. Therefore economy suggested that adjacent meters be selected, but not necessarily those with the same time limits. Furthermore, the budget constraint dictated that no meter be surveyed more than once. Thus, the overall sample size was set at 30 l/4-hr, 56 l/2-hr, 161 1-hr and 52 2-hr meters, comprising 19 percent of the total meters. Within these constraints, appropriate groupings of meters were selected from alternate city blocks in a random pattern spatially and temporally throughout the Central Business District during March and April, 1982. The hiring of suitable interviewers poses a serious challenge. These people must be trustworthy, sufficiently intelligent, inter-personally adept, well-motivated and available. Personal recommendations from known colleagues is one source. Advertisements in appropriate places is another. The size of this group must be large enough to accommodate a few absences due to illness or other temporary commitments, yet not any larger than necessary to do the job in the time available. Otherwise the cost of training and supervision rises unnecessarily. In the parking study, six individuals were hired through ads and personal contacts, of whom four were selected to form a continuously working crew, while the other two remained as backup for emergencies. This approach worked very well. Each person was provided with a coding manual that gave detailed instruction on how to translate the data to machine-readable form. Special information was provided for some of the difhcult questions, such as Nos. 13 and 14 in Fig. 2. The manual was adjusted in the first week of trial interviews to correct ambiguities, missing instructions and the like. Interviewers were also expected to submit Comment Sheets that highlighted all interesting developments observed during the day. By the
126
F. F. ERNST and T. A. LAMBE
start of the survey, the interviewers were very familiar, with the procedure. Since an 8: 00 a.m. to 6:00 p.m. coverage was desired, two interviewers worked from 8: 00 to 1: 00 p.m., and the. other two from 1:00 to 6:00 p.m. Because the meter groups were widely distributed, these people could not assist each other during busy periods, nor spell off each other with time for a break. Interviewers were paid for 6.5 hr to cover extra time for coding, especially needed following a hectic day at centrally-located l/4-hr parking meters, and to compensate for the absence of coffee breaks, etc., during the five-hour interviewing period. Machine-readable interview forms greatly facilitate the monitoring of job performance. At the end of each day, the collected forms can be listed on a computer print-out sheet for a quick visual scan to detect obvious discrepancies (e.g. missing meter numbers, misalignments, etc.) and such forms can then be returned to the appropriate interviewer for correction. Subsequent statistical analysis with standardized computer programs provide a further level of checking. However these checking procedures are not completely safe from fraud, in that a skillful interviewer can cover-up absenteeism by creating fake data that may not be detectable. Consequently, unannounced spot checking is a necessity for adequate supervision. In the parking meter study, the error rate detected by a visual scan was 50 per 1000questionnaires, and a further* 5 per 1000 were detected by the subsequent statistical analysis. All errors were due to the interviewers, as no problems whatsoever arose from the scanning equip- . ment. DATAANALYSIS AND RESULTS Although the sampling procedure establishes external validity, the assembled data should be subjected to a thorough analysis to check for internal validity[7]. This process includes consideration of the influence of temporal trends in interviewee behavior, of the impact of the interviewer’s presence on the foregoing behavior, and of the differences that may arise in the standards of procedure and interpretation used by the different interviewers (Instrumentation and Testing effects.) Following. consideration of these three aspects of internal validity, the data can receive a thorough statistical analysis to establish the presence of substantive relationships, the, principal procedure being the chi-square test. In terms of the parking meter study, internal validity was supported by the observation that no trends were detected across the two-months of the survey, that the parkers did not see the interviewer until they were on the point of driving away from the meters, that the number of observations collected on each day of the week was approximately equal, and that no significant difference in results could be detected between the interviewers.‘ Extensive pre-survey training and testing provided an equal standard for all interviewers, as it was important that they ask the questions correctly, and code the. responses in a similar manner. The loss of interviews as a result of multiple departures, or departures after 6:00 p.m., did not introduce bias. The miss rate was roughly the same (29-33%) for all meter time limits. Although greater at two high activity 15-min. meter clusters (near the Post Office and the Liquor Store), the number missed at these two locations was not likely to include users with different attitudes from those at other 15-min. meters. Multiple departures.
occurred randomly throughout the period; they were not clustered in the lunch hour, for example. The number of parkers who refused to be interviewed was small (about 40 out of 2500), and even if they were dramatically different from other respondents, their contribution would not have had a significant impact on the results. These non-respondents were typically busy executives, or people who had been interviewed previously. The data on parker behavior and parker attitude permitted the testing of a number of the hypotheses or beliefs commonly held by the people who formulate parking policy. Table 1 briefly describes the purpose of each question and illustrates the nature of the experiment. The primary hypotheses were: (1) Shoppers are the major user of meter space. (2) Demand for meters is very high. (3) Time violation and remetering are common occurrences. (4) Parkers value the convenience of meter locations. (5) Meter price is a major factor influencing people to come downtown. Table 2 shows that the purpose of the trip differs significantly according to the meter chosen. Shoppers provide the greatest demand for 15-min. meters, while business and social-recreational trips dominate the 120min. meters. The trends underlying these changes progress smoothly as the meter time limit increases, in part reflecting fewer shopping opportunities near 2-hr meters, and in part reflecting the influence of trip purpose on desired parking duration. With a total of 2581 interviews, the chance of these trends occurring due to random sampling error is negligible, the SPSS computer program giving a chi-square value of 240 for this cross-tabulation with 15 degrees of freedom. The combined figures, weighted by the number of meters in the city core, confirmed the hypothesis that shoppers provide the primary demand for meters. The length of time a person chooses to stay at a meter quite naturally depends on the trip purpose. It also depends on the time limit for the meter! As shown in Table 2, the median time at 15-min. meters ranges from 8 min. for Loading, to 31 minutes for Job related trips. For 120-min. meters on the other hand, loading seldom occurs, and the median time for Job trips is 116min. Undoubtably, the relative availability of the different type of meters in the preferred locations has a bearing on which space a driver chooses, all of these people arriving between 8:00 a.m. and 6:00 p.m. However, given that a person does select a curb meter, the parking duration is more likely to exceed the median for the trip purpose if the meter time limit is 120min. rather than 15 min. The distribution of occupancy time provides one measure of overall demand. Table 3 reveals that onethird of the people stay longer than the limit at I5 and 30-min. meters, 20% stay longer than the limit at 60, and only 7% stay longer than the limit at 120-min. meters during the period between 9: 30 a.m. and 4:00 p.m. For the day as a whole, the percentages exceeding the time limits are 35, 39, 24 and 20 respectively, where the numbers of parkers observed were 643,881, 1688and 247 respectively, for a total of 3459 vehicles. Thus the time limit is exceeded more often at the shorter-term meters. The distribution of vacant periods between successive users of a space provides another measure of demand. As shown in Table 3, one vehicle immediately follows another in 28% of the departures. The average time vacant tends to increase with the time limit of the meter,
Survey of people par&g at curbside meters
127
Table 1. Relationship of questions to issues
the
shoppera “re
primarp
m8tet weft demand for
meterparkin@
is very high vieXaCiono.
vioXatioas
vhy parkers
prefer
parkera value the convenience
I of meter locations I I 1 parker6are eensitive tO price: 1 f the major factor influencing
meters attitude
of parker
t* meterrate increases,
and reaeteriag
free
perkade parking. tlJrlWNW/priCe telafionships origin-destination
fat B subsequent
and frequency
I
I
Table:2, Trip
purpose
of traffic
study
flow
I
and median parking duration .6
c
I
PWpolL of
Trip
I I
I
Metar Time Limit
I
t t t IFHinutaE
I’ i
fD-SiIiautcs
40+4imtra
lZ#-?tinUtC*
OV?rtll t
t I
I
I I
I I
7.
Win.
1
X
Uin.
%
Min.
Z
nin.
X
Min. I
20
52
24
17
35
46
22
70
9
57
12
16
I8
2%
22
2g
28
30
22
28
4
21
11
33
9
32
34
57
15
52
6
31
6
20
a
53
1s
116
9
76
Load
I I 1
4
8
5
9
-
=
3
13
Other
t
3
7
4
13
6
17
5
Ib
Shop
t I Scx?Rec i 1
Business
Job
414 5
I7
I I t I I 1 I
I I
I I t i
OVeiall Bample
/ c
i i I
108 487
10
fOO bbl
22
100 1262
28
loa 165
51
loo
3l
1’ I *
F. F. ERNSTand T. A. LAMBE
128
Table 3. Percent distribution of occupancy and vacancy periods
,
W-
I
I
I Meter
1 Duration
Time Limit
(Minutes) 15-Minutes
occ.
>
VK.
30-Minutes
60-Minutes
occ.
occ.
Vat .
Vat.
IZO-Minutes
occ.
Overrll
Vat.
occ.
Vat.
100
83
100
76
100
74
100
60
100
72
> 5
74
32
07
32
91
28
92
36
90
31
>
10
48
18
71
20
75
19
81
27
74
21
> 15
31
11
60
14
65
14
73
22
64
16
> 30
13
5
34
7
42
9
50
13
41
9
0
I > 60
I
4
2
11
3
20
3
33
3
21
3
i I
i I
2
1
3
0
4
1
7
1
4
1
Avg. Min. i
14
43
10.9
33
I
,120
I Variance
I I I c
Sample
8.3
26
8.7
33
9.4
396
360
483
250
440
524
1025
135
but this may be due to sampling variability, the Fstatistic being 0.2 with 3 and 2120 degrees of freedom respectively. For the overall region, the vacancy rate was 20%, roughly triple that found in 1979 for a smaller sample in a central and localized area during the same period of peak demand [2]. Record selection, another feature of the SPSS computer program, enables special subsets of interviews to be assembled into a separate group for analysis. Thus in the parking study, those people having a violation sign showing (due to insufficient money in the meter) could be analyzed separately to detect the incidence of fines. The results showed that there was a one percent chance of receiving a ticket for a fine with every 5 min. that the meter showed the violation sign during the period from 8:OOa.m. to 6:00 p.m. With a $3.00 fine costing 15 times the hourly fee for the meter, the parker could expect to pay on average double the regular rate by taking a chance on not having sufficient coins in the meter. The foregoing observations do not include the 8% of all parkers who remetered in order to stay longer than the time limit without the violation sign showing, of whom a sixth returned at least twice to add coins. None of these people received a fine. Detection of remetering by chalking tires, or recording licence numbers, is a time consuming task for the Commissionaires. The incidence of remetering was significantly lower (2%) at 15-min. meters, as might be expected from
9.6
*
in contrast to 43% at 30 and 60-min. meters. This result is statistically significant, with a chi-square value of 33 on 3 degrees of freedom, and may be due to the lower relative convenience of garages, which were some distance away from the 2-hr meters. All respondents tended to qualify their interest in free parking with the requirement that the parkade had to be ‘close’ to their destination. It was fairly clear from the comments on the Interview Sheets that convenient access and proximity to their destination was more important than economic factors to most parkers. This is not a surprising result in this particular study, as the curbside meters offered both aspects, meter rates not having changed during the inflationary eight years since 1974. One-quarter of all people said that they would no longer use a meter if the rates were doubled, and most of these would park elsewhere. This result was independent of trip purpose, remetering and meter time limit, except for 15-min. meters where only 1% would be affected. However, of specific concern to the businessman was the potential impact of a doubling of meter charge rates on the number of people shopping downtown, and the potential offsetting effect of having free parking in municipal parking garages during the first hour of use (instead of the current nominal fee of $0.25). While four percent of all parkers said that they would shop or do their business elsewhere if meter rates were doubled, 75% of these people said that they would park in a garage if it was free for the first hour. Hence a negligible one percent of all parkers indicated that they would not come to town if meter rates were doubled while the garages were free for the first hour. Whether parkers will do on average what they say they will do is of course a matter for conjecture, but the attitude expressed by the parkers is an important consideration for City Council. In summary, the first five hypotheses of Table 1 were supported by the survey results, but the (second) one
129
Survey of people parking at curbside meters concerning high demand for meter space appeared to be relevant only to the most central area of the business district. CONCLUSIONSAND RECOMMENDATIONS
The results obtained from a well-designed survey should reduce uncertainty about the major aspects of the
problem facing the decision-makers. Thus these people along with their advisors must be consulted while the questionnaire is being developed. Furthermore, the use of a preliminary list of questions abstracted from previously available material helps to give a focus and coherence to the consultative process. Because many people along the chain of communication participate in the planning of the questionnaire, the results of the survey receive comprehending and interested attention, which facilitate transmission of the information within the relevant parts of the municipal decision-making system. In the case of the parking study, the results of the survey were presented in the form of a recommendation with supporting data. The principal recommendation was that parking meter rates should be doubled in the central region, while the nearby parkades would be free for the tirst hour of a parker’s use. This combination would make more space available at the curb meters for those who put high value on convenience, while providing inexpensive parking for those who are primarily concerned about cost. The survey had indicated that virtually everyone favoured most highly one of these two aspects, convenience and economy, but that hardly anyone would balk at going to the Central Business District because they did not get both together. Because the public clearly perceives the relative convenience and cost of each parking alternative, the report recommended a policy of maintaining a balance between these aspects for all such services offered by the municipality. In particular, the fee for using a curb meter should reflect the basic value the public puts onto this most convenient of parking locations. Such a fee should be at least as high as those at nearby commercial parking lots so that space always is available because excessive demand is avoided, fine tuning of demand being achieved by the use of shorter or longer time limits in special locations. Market rates also will tend to reduce the incentive for remetering. Furthermore, to encourage curbside parkers to put sufficient money into the meter when thev park. and not to over-stav the time limit. the
combination of fines and enforcement should be kept at an appropriately higher level than the rate charged by the meter. Parking garages can draw shopping and business trips to town by charging a very low rate for the short-term, while disuading excess demand from commuters by charging above-market rates for all-day parking. As demand for short-term parking grows, the City can construct more garages, using the funds from excess revenue over expense at parking meters. Demand for longterm parking space can be satisfied at commercial rates by private enterprise. Discussions arising during the presentation of the preliminary results to the Traffic Sub-Committee and to the Downtown Businessmen’s Association indicated that the division of authority between the foregoing Committee and the Parking Commission would continue to impede effective co-ordination of the planning for meters, lots and parkades. Consequently, to facilitate the implementation of changes in parking policy, City Council has approved a Bylaw that will restructure the committee system so that all relevant decisions will come under a single committee, instead of the current division between the Traffic Sub-Committee and the Parking Commission. Thus it can be expected that in the course of time, the foregoing recommendations will be addressed in the light of the survey results and the other considerations that normally impinge upon municipal decision-making. REFERENCES
I. T. H. Poister, Public Program Analysis, pp. 27-28. University
Park Press, Baltimore, Maryland (1978). 2. T. A. Lambe and C. D. Wild, Formulation and implementation of a pricing policy for municipal parking. Socio-&on. Plan. Sci. 14, 25-32 (1980). 3. CHEK Television, Interview of Ald. G. Brewin, Chairman of Traffic Sub-Committee, City of Victoria, 15 Oct. 1981. 4. C. Fornssler, Mayor McElroy, Mayor Pollen or Mayor Tindall?. Monday Publications Ltd., Victoria, B.C., Monday Magazine 7(12), 10-13 (6 Nov. 1981). 5. C. Fornssler, If elected I promise. Monday Publications Ltd., Victoria, B.C., Monday Magazine 7(13), 8-13, (13 Nov. 1981). 6. C. Fornssler, Taking aim at the incumbents. Monday Publications Ltd., Victoria, B.C., Monday Magazine 7(14), 10-21 (20 Nov. 1981). 7. T. H. Poister, J. McDavid and A. Magoun, Appl. Program Evaluation in Local Government, pp. 13-29. Lexington Books, Pennsylvania State University, Penn. (1971).