Energy conservation through urban transportation planning

ENERGY CONSERVATION TRANSPORTATION

THROUGH URBAN PLANNING

Roc;ri~ E. CARRIER The Pennsylvania

Transportation

Institute,

University

Park, Pa 16802 U.S.A.

Abstract-A large number of techniques for conserving energy in urban passenger transport are described. A systems approach for evaluating these simultaneously in order to formulate areawide passenger transportation energy policy is presented. It consists of a simple computer technique for estimating the conservation value of various schemes. The program is also of value in assessing the energy impact of individual energy conserving programs. Because only local planners are familiar with the economic. environmental. and political constraints on policy and programs, the tool is intended for use in urban regions. It is, however. written in general terms and as such. if used in all urban areas in the U.S., could offer realistic national estimates of urban passenger transportation energy requirements in the short term(@ IO yr).

demand confrontation will no doubt be a coordinated program of increased supply (through expanded domestic exploration activity augmented by increased imports) and reduced demand growth rate). While the degree to which conservation programs should be pursued is purely economic (the trade-otf is between the long-term benefit ofprolonging the finite supply of fossil fuels and the short-term economic benefit of rapid consumption), there is no doubt that certain changes in the existing transportation system could conserve fuel with very little economic and social impact. Certain conservation programs are clearly in the best interests of society. Since about 75 per cent of the total transportation energy consumption is consumed by the highway mode and since about 75 per cent of the population of the U.S. live on 2 per cent of the land area, conservation effort should logically be addressed to urban highway use. At least it appears that fuel savings from urban passenger conservation programs could bc substantial.

The energy problem in the transportation sector has been adequately described in the literature. The short term problem (0 IO yr) is charactorked by: (9 Rapidly expanding energy use. The transportation sector presently uses about one-fourth of all U.S. consumption and more than half of the U.S. petroleum consumption: (ii) A shortage of low-priced domestic petroleum, the fuel which comprises more than 95 per cent of the total transportation usage. No other fuel offers the same prerequisite for mobility. i.e. high energy content per unit volume. As noted during the 1Y7331974Araboilembargo.ifthere isno oil, there is virtually no transportation; (iii) Conflicting domestic demand for the various refined products. Opinion is growing. for example. that crude oil should be used only for production of petrochemical products (e.g. plastics) since petroleum is the non-replaceable base for those products. Automobiles can perhaps be run on other fuels such as hydrogen or electricity; of oil supply in the (iv) Possible rapid curtailment future through politically motivated embargoes by OPEC countries. As the percentage of U.S. daily consumption supplied by imports continues to grow. the situation becomes potentially more dangerous. The solution to the short term energy suppiyt Numbers

rn brackets

Ejicirncy

twnds

Rice [1,2]t, Hirst 133. and others [4,5] have examined energy eficiency trends in transportation. With increasing auto dominance in recent decades U.S. transport efficiency has dropped substantially. Transport efficiency-Rice suggests the term “net propulsion efficiency” or NPE-is frequently measured in terms of net cargo ton miles or passenger miles per gallon of fuel. However. as Lill[6] points out, the NPE measure is deficient as a base for a systems evaluation because

refer to the list of references. 493

it does not include any measure of the level of service otTered. He states

three areas: Mode shifts. intratnodal \ehiclc ellicicnc! improvements. and travel demand reduction (reducing vehicle miles of trawl. VMT).

Priwtc

Rcilecting on Lill’s statements. the NPE statistic is delicicnt for passenger transport as well. Obviously v+alking or bicycling is the least energy intensive mode of urban transport. Therefore. judged solely on the NPE basis. automobile travel should be replaced by walking. air travel by automobile. etc. The NPE statistic is likely to be of limited value in setting specific urban passenger energy poliq. To be totally effective it must be incorporated with some tneasurc of level of service. Unfortunately

i rapid transit These shifts can hcst be accomplished by mode shift incentives and the so called “attto disincentives”.

Mode shift inccntiws

the present mcasurcs of level of

service at-c zither wry cotnplcx or grossly unsatisfactori. Ncvcrthelcss. Rice 171. using the NPE statistic to suggest changes. states that providing for increased travel

in the decades

IWO 20(X) while

holding

a~~t~ual

pctrolettm consumption at the I970 Icvel or less is possible through the USCof the more etlicient tnodes ol trnnspoltation. k\b:KG\

(‘OhSLKVATIOU

C KRAR

PASSENGER

A multitude of conservation techniques have been suggested in the literature. Generally the intcnt of these in concert

with

the goals

of cvisting

urban arca programs. For example. existing programs to reduce highway congestion requit-c traftic tlou improvemcnts

or

;I

shift from private

automobile

Auto disincentives

cuclttsiw lanes (cg. bus and carpool lanes. ttrhan area hike-bike trails) transit promotional campaigns transit lowl of service improvements (c.g. improved schedules) park and ride lacilities institutional cliatigcs(c.g. industrial fbrc refund polich. staggered working hours)

I

pat-king bans parking surcharges conyestion toll5

2. Irtrr-wt~otl~l ~~//ic~i~w~~ i,r~/,~,orr,,t~c,~~r\. This cntcgorq inclttdcs and technique I\ ithin a given mode of transport (hcncc “intramodal”) which increases vehicle elticienc>,

TK.2\SPORT

schemes works

walking carpool \anpool

attto to:

to car-

pools ot- transit. both of which enhance energy eflicicnq. Perhaps the ewicst wan to rcdttcc air cmissions and thereby enhance air quality is to limit the vehicle miles of travel (VMT) in urban areas. These and other 1ransportation control strategies ofier cnergl conservation ax a by-product. 4s sttgqted nbovc. tnan) programs for energy conservation exist. The following summa-q i, limited to those u hich provide savinp in urban passenger transportation. The list is also limited. in general. to short term solutions (0~ 10 cr). Programs arc categorized in

Increase K!hlClC

clticiencq

transit bus private ;tttto shift to serbicc vehicles (e.g. motorcqclcs. urban vehicles) shift to non-petroleum based prime mo\er.:

C‘crtain changes tn \ehiclc hardwrc policy would conserve enet-p!.

Hardware

and operating

t-educe weight (perhaps local wzipht rcpressivc ln\i. or manttfaclurer tnandate) standard transmission rather than automatic radial tires rather than conventional dicselorclcctriccngines rather than spark ignition improve pwvcr-to-weight ratio (perhaps local horsepower tax) rclzt\ emission controls rcdttccd use of pow i’i- accessories (or increased etlicietiq of same) axle ratio or transmission gear ratio changes (e.g. ovcrdrivc)

Energy conservation

Operating policies

\

through

tuning maintenance (perhaps local inspection programs) speed reductions (arterials) improved traffic flow (e.g. right-turn-onred. off peak flashing cautions, urban area by-pass, ramp metering) anti-idling policy taxi-cruise restrictions

3. KblT reductions. Many schemes have been suggested to reduce travel demand. Each requires either a decision and subsequent mandate by local government or a voluntary attitude shift by the public, i.e. an examination of the necessity of each trip.

, AFZ (auto fret zones for shopping

VMT reduction

(

etc. also called MVE policy or motor vehicle exclusion) local gasoline taxes reduced gasoline availability (e.g. Sunday service station closings) improved communications devices van delivery (groceries, etc.)

Mugrlitude o~‘saving.s possible Husted 18) has calculated the effect of some of the changes just described. These are shown in Table I. While the calculation assumptions are very general and are thus subject to some question, the reader should note one point of prime importance. It appears that for the two groups of hypothetical situations postulated, private vs public transit, the biggest conservation potential lies with changes in private transportation, i.e. automobile efficiency. The reader might perhaps anticipate this result, Transit simply does not serve a high percentage of the demand. Even if present bus ridership were increased to capacity, transit would still not be able to serve large mileage generating trips Table

Hypothetical

transportation

progam

planning

495

such as family vacations and peripheral (cross town) as opposed to radial (to and from city center) trips. In terms of total mileage, these are the fastest growing types of trips, While Husted’s hypothetical program suggests 50 per cent of urban commuters shift to transit, there is some question of the transit bus manufacturing industry’s ability to meet the hypothetical demand. The foregoing statements should not be viewed as an attempt to minimize the value of transit as an energy conservation measure. Indeed, transit has already proven a viable conservation technique in most cities. Rather, the author has attempted to characterize the need for a careful evaluation of suggested conservation programs. Obviously, the most emphasis should be placed on those programs with maximum conservation payback per unit of social and economic cost.

Real world solutions must have the long term bdcking of the political and economic infrastructure. This is not likely to happen spontaneously. Should it happen, it may be on a piecemeal basis. motivated by vested interests. As such. the new programs would not be integrated with other complimentary programs and the net effect may be undesirable. Park and ride facilities, for example, are not likely to encourage transit use in an area where busses are already crowded. Projects such as traffic signalization, one way channelization. exclusive bus lanes, and/or park and ride facilities require funding. Programs such as transit promotional campaigns, parking bans, local gasoline taxes. local Sunday service station closings. or auto free zones rcquirc rntcnse political backing as NXII as funding. Since funding transcends all else in shaping urban policy. the following proposal is set forth. Subject to a moratorium on federal transportation planning funding, each SMSA or regional planning

I. Fuel conservation

Public transit 5@;,, city commuters shift to mass transit Eliminate 50”; traffic congestion Get 50”;, driver-only urban commuters to carpool 50;/” shtft of intercity auto to bus and rail Shift SO”< short-haul air traffic to inter-city bus Private transit 50:: conversion to small cars 50:; conversion to fuel economy vehicles Achieve 50;~; success limiting speed to 50 m.p.h. Get SO;,, of people to walk up to 2 miles 7 From Ref. 8.

urban

options) Total transportation energy conserved (‘I,,)

2.7 1.6 > 2.4 2.5 0.7 8.0

I 2.0 2.8 I.8

commission shall be asked urban passenger transportation plan.

The heart

of this plan

devise

to

an acceptable

energy

would

conservation

be a systems

actually tion

analy-

dependent

sisomploying data already existing in the regional planning ottices. Given that such a plan here carried out adequateI! in all urban areas in the U.S.. it would pro-

lion jobs.

vldc ;I statement

sharply

Ob\iousl!. energy

this

and policy

lx made may

to urban

arcas

energ!

tolcrablc urban

in the arca

as mandated perhaps

it attempts

problem

automobile

of the city would air qualit!

conservation

to correct

a sympto-

without

dealing

use in the urban

energy

consumption

certainly

some

with

have

areas

pollution

the in

conceived would

pcr-

abatement

many

changes

energy

can

be made to im-

elticienq.

Some

low

social

l1.S.

cconomg.

which

cause

simpl!

thcrc

not be

arc

man>

changtx M hid1 would pener-

while

and

Yet,

than I3 mil-

conscr\-inp

implemcntcd

Il~el. Thcsc as soon

must

as possible.

impact

(upgrading

demand

foi- thcsc the

such

these

vehicles

then.

The question

not

suh-

product

demands.

As

nc~

economics.

represent

of pro~r;im

lx ans\\ercd

liar \I ith the constraints the judgcmcnt

products

c\istinf

ma>

implcmentahllit~ 1,~ local pcoplc

in the local

as to ho\\

and

SL~C-

\I ho XI-Ufami-

;irc;i. For example.

successful

exclu-

;I proposed

sivc bus Innc will bc in causing niodc shifts along some urban artcr! can best hc made h! local planncrx. Thcsc planner2

li3bc existin, (J data

cent

transit

their

;II-C;I. l.o~~c;~ll~ can

ridei-ship

on trattic

\olunics

and

pci

a\ well a\ si-
fat

1111’11.the ~-cyic~nal planning

make the the best Iudgcmcnt is implemcntahlc

and

aFen;I> to \+ hethcr a

the dcgrcc

of success

may achicvc. It is not lopical to cupect these be formulated at state or fcdei-al Icvels.

plans

it to

of these

efficiency of existing automobiles. for example) while others have potentialI> insurmountable shortcomings (locally administcrcd horsepower taxes for example). The dccision as to how much ettbrt should bc expended in making ;I ch~igc must be based on the potential conservation SLICCCSS.The relative merit of conservation programs can be discerned only when a systems analysis is performed. In a systems analysis, all techniques arc considcrcd simultaneously, allowing integration of the more s~~cccssful and compatible programs into an optimal schcmc. oiler

ma!

reduce

program

earlier.

changes

stantiall!

cxs

transportation

term

manulilcturc

ate new economics

ccs~~c;in bat

the effect

A properly

in urban

for

by the Act was

(cnergq

there.

plan

that

programs.

As stated

some

auto

transportation

be invcstigatcd

for more

generating

The

haps negate the need

pro\e

accounts

short

is and

ducts.

plans

In fact,

(air pollution)

of improving the

in-

Therefore.

economy

manufacture

cars. vans for \anpools. small busts for jitney and the like may bc considered as new pro-

in that

Reducing

certain

of

energy

planning Icvcl. this plan has certain sim-

that

air quality

inp systemic

the queue

an actual

transportation

I6 per cent of the U.S. GNP. rcduccd

I1.S.

Small

directed problem

give

the

on auto

scrva

poorly

area).

for managing

federal

also

use. Highway

degree

at the prqjcct

Air Act of 1969.

matic

to

It would

to ;I large

C‘lcarl~

note

Clean

underl!

\aluablc

hc

For the first time.

The reader larities

fuel consumption.

makers.

a perspective

prqjccts.

put could

national

would

plan

planners

local arcas urban

of future

anti M hat dcgrec of conscrva-

bc implemented

SLICC~SS is likely.

the

Before :I fuel impact statement can he made. two important questions must bc answered. Can the changes

Soniccncrg~ con5cr\;ltion propos;iIs i-cquirc projects which ma> not aff,ct the cntlrs urban arca. Examples arc vanpool programs (onI! atfect traftic in the industrial sectors), cvclusicc hic!clc-pcdestriall right-ofways (hike-bike paths arc limit4 in certain areas because of propcrtl ;lcquisitlon. topography. etc.). and exclusive busl~ines (can onl! lx implemcntcd along high density corridors synch as major ui-ban arteries). Other progi-anis ma! atfcct the cntirc ai-ca. MI& as conservation through impro\cd clticicnc> automobiles. <‘lenrl!. optimization of i‘ncrf! con5crvution must bc a coordinated combination of simple \-~ablc techniclucs. To ;ISXSS the clTcct of complcmentaq and simultaneous all links,

programs

the computer

actin g on specific can

lilcllitatc

links?

or on

the calculations

for the ncarl! intinitc \ai-let! of combinations. In the final analysis though. the cstlmatc of conservation program SLICCCSSmust ultimately be :I ,iudgcment made by planners. The computer can onl! assist in that .iudgement. Planners can also dra\i guidance in their decls~ons from the pcrformancc of similar facilities \+hich

Energy conservation

through

have been tried in other areas. A computer model is presently being developed and tested at the Pennsylvania Transportation Institute. This prototype model will be completed by September 1974. and is intended to aid planners with energy systems analysis. The remainder of this paper describes the scope, limitations. and operation of the model.

The mathematical model employs a scenario approach to estimate the effects of coordinated energy conservation projects in an urban area. It simply calculates in a link by link fashion the fuel consumed for some base year traffic flow (say 1975) and then compares that with an estimate for the predicted flow under different demand satisfying systems. For example. scenario one might be the 1975 travel demand in Pittsburgh. Pennsylvania, satisfied with the transportation system and modal split which exists today. The model calculates an estimate for the fuel consumed on each link based on the base year traffic assignment. If traflic estimates exist only in the planning commission’s planning package for, say. 1973 and 1980, a straight line interpolation of 1975 traffic flows will suffice. Then. after imposing an exclusive buslane, generally smaller automobiles, or some combination of several conservation on the 1975 transportation demand programs (scenario two), the link consumption is again estimated. The difference in these two estimates provides a conservation estimate for the programs considered. The model is intended for use by regional planning agencies in any urban area throughout the U.S.

lr1put Most of the required input is presently available on local planning agency computer tapes. Other information from the literature has been input into the model as constants. Three types of information are required: (1) Passenger movement eficiency-this information. in terms of passenger miles per gallon, requires knowledge of automobile efficiency for the various vehicles, the different types of autos on the links (mix of vehicles), average auto ridership, transit bus ridership and bus efficiency; (2) Demands estimates-~thcse have been made bq planners in units of vehicle miles of travel or daily vehicle volumes on each link: (3) Type of project being considered--largely, the identification of links which will be affected by some proposed project. t Note that the consumption of rapid rail or trolley transit is not included in the calculation. This was intended since these modes do not generally consume petroleum.

urban

transportation

planning

497

Input described by items 2 and 3 above must be made by the regional planning agency. Item I above. vehicle efficiency. is somewhat more difficult to deal with. However, as described in the following paragraphs. passenger movement efficiency information has been collected and input into the computer pr”gram. where possible. as constants.

Because of the methods of fuel distribution by wholcsalcrs. fuel tax collection by state and federal governments, and fuel consumption bookkeeping, consumption data are not broken down for SMSA or regional areas. In this research effort, consumption for the urban region was estimated on a link-by-link basis. Link consumption can be calculated from:

where T/MT = vehicle miles of travel (the product of link length and traffic volume), MPG = vehicle efficiency, and C, = link fuel consumption. Summation of CI values over the entire region gives an estimate of regional consumption. The bulk of fuel used for passenger mo\,cmcnt in urban areas is consumed by automobiles. Because auto consumption far outweighs transit consumption. the precision of m.p.g. estimates for transit vehicles may be very low. For purposes of this research. an estimate of 5 k 2 m.p.g. was used. Conversely, it is very important to estimate auto eficiency as preciselq as possible. For a typical link, + I m.p.g. in auto efficiency provides an automobile consumption range which is much larger than the total bus consumption. Much data are available from a variety of tests on automobile fuel efficiency. While it would be desirable to statistically relate and rank those factors which are most important in altering m.p.g. etficiency. it is not possible since the data have been collected undcr a wide variety of driver. driving cycle. and vehicle hardware conditions. Ford Motor Company reprcsentatives [9]. however. have published regression analysis information on vehicles run in somewhat standardized conditions. The resulting equation has the form: m.p.g.,

= KX-“Y-*Z-’

where m.p.g., = miles per gallon for some 161 automobiles, K = a constant, X = auto weight. Y = engine displacement, Z = axle ratio. and (1. h and c‘ are constants. Similar data are also available from the Environmental Protection Agency’s dynamometer tests on 1973 and 1974 model year automobiles [IO]. These tests were run principally to determine if the vehicle

meets emission standards on a 7.5 milt: simulated urban drive cycle. MPG cstimatcs arc mndc from the carbon balance cquati0ns.t In the program. the aforementioned vchiclc m.p.g. vatucs wrc used along with data on specific operating characteristics which inllucncc consumption (speed. gradient. stop go q&s. etc.). Thcsc arc dealt with in

[ 1’71Llj]. Auto weight is the single most important vchiclc characteristic which affects gasoline mileage. Thcrefort. for the put-pow of this analysis. automobiles \i\ere divided into four weight categories: luxq. standard. compact and subcompact. The tnix of vchiclcs on the road. i.e. the number of compacts. subcompacts, etc. is changing with time. In this study. the mix was cslimated from I’973 sales records. Four “composite” autos were assumed to represent the weight classes and :I base m.p.g. estimate was made for each. From this. the estimated link automobile etficienc) was calculated and modified depending upon the specitic operating characteristics encountcrcd on that linli (e.g. the number of stop or slow down qclcs. traftic wlume. and other link characteristics 11hich alTcct m.p.g. cllicicnq ).

The output of the model consists comparisons of estimates of fuel constmicd bq various conservation programs. These estimates of fuel consumption are arranged in array tables. each arra! being ;I tabulation of the anticipa(cd savings based on wmc pcrccntagc success of the project. Intcrpt-ctation of the output requires that the planner snter rhc array Lrblcs. cstimate the st~cccss of the project (e.g. cstimatc the pcrcentage ridcrship incrcasc along sonic specific nc~ exclusive bus lane). and then add this consumption cstiniatc (0 that dcriwd from other conservation prw jccts (cg. add the estimated husuu) savings to savings dtic to rcduccd auto weight or other cotiscrviilion programs). There arc essentially only tv, o viable techniques fog conserving energy in the short run. improving vehicle ctlicicnq (largel) auto ellicicncy) and rcduccd aillomobile ttse (a small reduction in person trips coupled with the mode shifts. auto to transit. bicycle. and walking). To prolidc an cxamplc of the model oufpttt. arrays are shown in ;I series of tubleh. These tables arc examples of the output fol- an urban ;Irea of about onchalf million people. Tables 2 and 3 provide varivble succexs cstimntcs 01 sacings possible through the aforementioned two cow servation techniques, mode shifts and automobile ctlicicncy improvements. They arc based on calculations over cvcry link of the SMSA (or planning rcglon). Table 4 provides ;I composite estimate of thcsc two tcchnicluea. again calculated obct- all links. In each cat. the success of2 gi\cn shift or m.p.g. improvement can bc compared with the /era xucces~ estimate (no change from present politics and programs).

Energy conservation

Table 3. Output

through urban transportation

VMT

IY73 X3.748.506

2.395.708 7 71 I.423 2:05X464 1.796.78 I 1,597,139 1,437,475 1.306.750 1.064.759 XY8.3YO

0 I 2 4 6 8 IO I5 20

499

array l’or improved auto efficlcnc) Annual

Improved auto eficiency (m.p.g.)

planning

fuel consumption cstlmate (gals) for all links. SMSA lY74 31.623.356 2.635.27’) 2.432.565 2.25x.x I I

1.976459 1.7.56.853 1.5X1.167 1.4?7.J25 1.171.235 YXX.77Y

1975 34.49x.207 2.x74.x50 2.653.70X 2.464. I 57 2.156.137 1.916.567 1.723YlO 1,5&l00 1277.71 I 1.07X.06X

This tnblc assumeb auto traltic remains as projcctcd l’or each year in the Tuturc but that average Il~cl clliacnc! proved. It is presented only to indicate the magnitude of energy savings possible through improved auto ctlic~cncy.

While Tables 2. 3 and 4 provide an overall estimate of fuel savings possible in an urban area. they do not offer information on the relative merits of specific projects, such as speed limit reductions on certain arteries. The question remains then, how shall the planner estimate the impact of specific projects. Some programs will affect consumption throughout the urban area (e.g. smaller automobiles). Others will affect only specific links or zones of the city (e.g. exclusive buslanes). The model has been programmed to deal with the following projects:

I. Affecting al/ links

Two array tables (Tables 5 and 6. one from each category) are given here to provide an example of the output.

demand change (reduced auto trips) auto weight reduction (all trips) increased average riderships (all trips) exclusive bus lane exclusive pedestrian-bicycle

right-of1. Affecting W”j < park and ride facilities .spWi$c links speed reductions (arteries only) by-pass routes \ auto free zones Table 4. Combined

Success of programs (improved auto etticiency +reduced link few)

ia im-

The strength of the areawide conservation plan rests on the planners ability to estimate which programs are implementable in his area and subsequently. on the planners estimate of the success of those projects. To aid the planner with this latter estimate. a study of the successes of various conservation projects in cities where they have been implemented is underway. Of course, these successes are not directly translatable from one urban area to another. While the Washington. DC. Shirley busway mode shift cxpericnce may not occur for a similar project in Pittsburgh. for example. certain similarities may exist and be of value to the planner. It is not within the scope of this paper to summarize impacts of the manifold experimental programs here. The value of the arcawidc conservation plan and the consumption values it generates depends

programs ol’reduced

auto use and increased auto cificiency

Annual fuel consumption cstunate (gals) for all links, SMSA lY73 IY74

3975

0 m.p.g.;O”,, I m.p.g.:2”,, I m.p.gJ’4”,, I m.p.g./6’,,

2.3Y5.708 2.167.195 2.12966 2.07X.738

1.635,27!, 2.3x3.9 14 2335,263 ‘,2X6.61 I

7.874.X50 2.600.6.14 1,547.559 7.494.4X5

2 m.p.g..2” II 2 m.p.g.,:l”,, 7 m.p.g., 6”,,

‘.012,39S 1.971.326 1.930.256

?,?I 3,634 2.I68.358 2. ILVX’

2.414.874 2.X65.59I 2.3 16.308

20 m.p.g.;25”,,

673.793

741.172

808.551

hlXlAH\

hl

This niimbcr

urban &xl

papu

IXIX

01‘sliort

a~temptcd

term

passenger

and

Transportation systems

wits

save encrg2. A gut

&al

consumption wlicii

arc

tion provides possible

incluclcd

complimcntcd thtxxqh

various

State

Ilni\cr\it!‘\

the conservation of techniques

in the

to

The ~~~od~l LIXS

or existing

to

~cliiclc

This inl’wma-

Ibrecxt

I\ ilh satimatos

tcchniqtu.

;I

potcn-

designed

data on

model.

with travel

loc:d planners

planntm

in

has been developtxi

Institute.

~~pproach 10 e\aluatc

tial of ;I coordinated

tion.

model

;I

llizl

with the merit 01’

Pcnns~l\ani~i

Rcscarcl~

togetlw

To aid

sytematicallq

;I computer

17~ rcsc;i~-chci-s at tlic

bring

Ihr conscning

transl70t-t;ltioll.

qi~antit~itiwzl~

each program.

to

tccliniqucs

inlbrniaof s;i\ ings

Energy conservation

through

9. LaPoint C. (1973) Factors affecting vehicle fuel economy, Reprint from Scptcmhcr IO, Society of Automotive Engineers Milwaukee Meeting. Puhlictrtim No. 730791, 1Ip. IO. Federal Register. Tests on both 1973 and 1974 model years are available in the register. I I. Environmental Protection Agency. 4 Report WI Fuel Ecommy. EPA, October 1973. 39~. 12. Claffey P. J. (1971) Running costs of motor vehicles as affected by road design and trafic, National Coopemtiw Hiyhwtr~~Rewrr,c/~ Pmqm~ Report No. I I I. 97~.

urban

transportation

planning

501

13. Austin T. C. and Hellman K. H. (1973) Passenger Car Fuel Economy--Trends and Influencing Factors. Reprint from September IO, Society of Automotive Engineers Milwaukee Meeting. Puhlicution Vo. 730790. 36p. 14. Cope E. M. (1973) The Erect of Speed on Automobile Gasoline Consumption Rates. Highway Statistics Division. Federal Highway Administration, October. Xp. 15. Huebner G. J. and Gasser D. J. (1973) Energy and the Automobile~General Factors Affecting Vehicle Fuel Consumption. Enury~ und tllr Automobile.Society of AutomotirY~ Eilglmvrx SP-3x3, pp. 25-29.

R&sumC~~On decrit un grand nombre dcs techniques permcttant la conservation de I’L:nergie dans les .transports urbains de voyageurs. On prisente unc approche systkmatique pour lcur ivaluation simultan& ce qui permettrait de formuler une politique relative ii l’L:nergie en mat&e de transports de voyageurs pour tout un sectcur. Cette approche cst une simple technique d’informatique permettant d’estimer I’intCrPt de divers plans au point de vue de la conversation de l’energie. Lc programme est egalement int6ressant lorsqu’il s’agit d’evalucr l’effet Cnergktique dc divers programmes distincts de conservation de I’encrgic. Comme seuls Its urbanistes et services de planification d’un endroit connaisqcnt B fond les contraintes dans le domaine kconomique, politique ct I’cnvironnement qui affectent les dicisions prises et les programmes, cet outil est destink principalement aux zones urbaines. Toutefois. il est r&dig& en termes @nCraux et. en coniquence, s’il Ctait employ6 dans toutes les zones urbaines des Etats-Unis. il permcttrait d‘Ctablir des evaluations nationales reahstes des besoins d’t:nergie pour les transports urbains de voqageu~-s it court tcrme (&~lO ans).

Zusammenfassung Der Bericht beschrcibt 7unlchst eme Vielrahl von MaBnahmen zur Energieeinsparung im stldtischen Personenverkehr. AnschlieRend wird ein systemtechnischer Ansatz erlautert, nach dem diese MaBnahmen simultan betwertet werden ksnnen, urn tin umfassendes Energiesparprogramm im Personenverkehr LU entwlckeln. Der Ansdtz beruht auf einfachen ADV-Verfahren zur Ermittlung der bei unterschiedlichen MaRnahmebiindeln zu erwartenden Energieeinsparungen. Weiterhin kann das Rechenprogramm such zur Bestimmung des Erfolgs einzelner SparmaBnahmen benutzt werden. Da nur die in der Stadtplanung tiitigen Fachleute mit allen Gkonomischen. umweltbedingten und politschcn Einwirkungen auf Mannahmen und Programme vertraut sind. ist das Verfahren speziell auf cinc Verwendung im sthdtischcn Bereich Lugeschnitten. Es benutzt jedoch allgemcin giiltige Ausdriickc und kiinnte daher sofern es in allen Stldten der U.S.A. verwendet wiirde-dazu beitragen. realistische Voraussch;itzungen des Energiebedarfs im gcsamten stgdtischen Personenverkehr der U.S.A. wlhrend der nachstcn IO Jahre jru erarbeitcn.