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A knowledge-based system approach to work shift selection for multilane highway reconstruction and maintenance projects
65
Recent Doctoral Dissertations a right-turn maneuver. Three surveys of driver and pedestrians were conducted to determine their understanding of pertinent laws and traffic control devices. The results indicated that drivers were less likely to know that they must yield to pedestrians when making a left turn. Also, drivers over 75 years of age were found to be significantly less knowledgeable than other age groups about the need to yield the right-of-way to pedestrians when making left or right turns at signalized intersections. Pedestrians’ knowledge of pedestrian signal indications was also evaluated. The results of the survey indicated that pedestrians over 75 years of age were not as aware as younger pedestrians of the potential conflicts with turning vehicles during the Walk indication. Also, pedestrians’ age and knowledge in regard to the flashing Don’t Walk clearance indication were found to be inversely related to each other, with older pedestrians having less understanding of the indication than younger pedestrians.
PRICING
Evaluating the joint implementation of congestion pricing and driver information systems. El Sanhouri, lbrahim Mahmoud, Ph.D. Massachusetts Institute of Technolo~gy, 1994. Supervisor: David H. Bernstein. In this thesis, the joint implementation of congestion pricing and driver information systems is analyzed. After selecting specific pricing and information systems from among the many possible choices based on representativeness and implementability, a modeling framework is developed that analyzes the interaction of the two systems in the presence of incidents, or short-term reductions in network capacity. First, the impact of toll stations is examined by looking at the benefits and costs when stations are either upstream or downstream of the points of congestion. It is found that downstream toll stations distort the arrival times at the toll stations, resulting in toll costs that may be hard to predict. In the upstream case, negative net benefits in costs including tolls were occasionally observed. This occurred when the information system increased the total number of toll paying travelers. Modifying the information systems through reducing guidance rates eliminated or reduced this problem. Two modified pricing systems were also examined. The first consisted of tolls that were Identical across routes for better implementability. A side effect was that revenue-increasing switching was eliminated and negative benefits no longer observed. In the second, only one route was tolled. In that case the optimal route split may not be attainable because Ideally we would like more travelers on the tolled route than is possible .with the restriction on the untolled route. Finally, superadditivity was examined and it is found that for our model, only simple additivity holds. tCopies available exclusively from MIT Libraries, Rm.
14-055 1, Cambridge, MA 02139-4307. 617-253-5668; Fax 617-253-1690.)
Tel.
Quantifying the effects of road pricing on roadway congestion and automobile emissions. Beamon, Benita Michele, Ph.D. Georgia Institute of Technology, 1994. 108 pp. Director: Paul Griffin. Order Number DA9511564 For years, transportation professionals have been engaged in an effort to ease congestion and reduce air pollution on roadways throughout the United States. In spite of these efforts, increasing roadway congestion and poor air quality are facts of life in most urban areas. Increasingly constrained funding for roadway improvement projects, coupled with more stringent environmental legislation, make the task of improving the quality of roadway travel even more difficult. Largely due to these facts, road pricing (direct charges assessed to travelers for use of specific roads during specific time periods) as a method of accomplishing functional and environmental goals, emerges as an attractive alternative worthy of investigation. Although there has been a considerable amount of research on road pricing, there has been little significant progress made in actually quantifying the congestion and environmental effects of such programs. In this research, a model is developed to quantify the reductions in congestion and automobile emissions resulting from two types of road pricing implementations: a Five-Dollar Cordon Scheme and a One-Dollar-Per-Mile Area Link Charging Scheme. The policy issues and possibilities for implementation of road pricing in a democratic society are also investigated. The model results indicate that both schemes are effective at reducing the number of blockages, but only marginally effective at increasing average rush-hour speeds. Both schemes were also found to reduce the amount of automobile emissions of carbon monoxide, nitrous oxides, and hydrocarbons. Except for reductions in nitrous oxides, the Cordon Scheme outperformed the Link Charging Scheme in every other emissions category. Based on these results, a number of recommendations are made which are designed to encourage political acceptability of a road pricing program. Finally, potential areas for future road pricing research are identified.
PROJECT MANAGEMENT
A knowledge-based system approach to work shift selection for multilane highway reconstruction and maintenance projects. Ahmed, Quazi Amin, Ph.D. The University of Florida, 1993. 234 pp. Chairman: Ralph D. Ellis. Order Number DA94-31901
66
Recent Doctoral
The timely, efficient, and quality completion of highway projects partly depends on the selection of the appropriate work shift. Certainly there are advantages and disadvantages for both day and night shifts. Daytime operations are generally considered to be safer for both workers and motorists because of better visibility and a higher state of alertness. However, to accommodate the flow of higher daytime traffic volumes, work zone lane closures may not be possible, and the option to work during the night becomes a serious consideration. A highway project’s characteristics may favor a particular work shift. Type of work, lane capacity, average daily traffic (ADT). work zone accidents, project duration, and project costs are some of the issues that may dictate shift times. This research is aimed towards the development of a decision model that will incorporate all the factors that may influence the selection of either a day or a night work shift. The process is based on a decision tree representing qualitative and quantitative factors, ranked in the order of importance. The shift selection methodology is similar to the human reasoning process and that is why a knowledge-based system approach has been chosen for this decision model. An expert system shell has been utilized to develop the knowledge base, which consists of IF-THEN logic rules. The rule-based knowledge structure also has the option to interface with an external traffic count database for the purpose of lane closure analysis. The model approach to work shift selection includes mathematical reasoning in the analysis of traffic congestion, vehicle accident numbers, motorist (user) costs, and project (owner) costs. The final solution offered by the knowledge-based system model consists of the recommended work shift, number of daytime lane closures allowed, user cost savings for a night shift option, and percent change in total owner cost for a nighttime alternative.
A multicriteria decision-making approach for evaluating alternative transportation plans. Driggs, Raul, Ph.D. Unirrr-sir!: of Miami, 1994. 541 pp. Supervisor: K.G. Zografos. Order Number DA94-26870 The reason for the selection of this particular research topic stems from the perceived need to establish some sort of “standard” to serve as a guide for the professional involved in this type of work at the Project Development and Environment (PD&E) Stage. Potentially inaccurate results are generally derived due to deficiencies in five basic problems areas: (I) lack of clearly defined goals and objectives, (2) absence of weight assignment, (3) lack of sensitivity analysis, (4) criteria duplication, and (5) lack of alternative segmentation. The principal objective of this dissertation is to establish an evaluation methodology that can effectively deal with these five problem areas. Another objective involves the identification of a technique to fairly gauge the relative weight of each
Dissertations
of the judges’ decisions and to properly aggregate the results. A discussion concerning the advantages and disadvantages of various existing multi-objective techniques was conducted. In addition, a panel composed of several PD&E professionals was asked to perform a multi-phase evaluation using various evaluation methodologies. Once a “potential preferred technique” was identified, changes were made to specifically address the five problem areas mentioned above. Finally, a case study intended to test the adequacy of the proposed methodology was conducted. The proposed evaluation methodology promotes the clear definition of goals and objectives by listing up to 147 different criteria normally encountered in transportation projects. The criteria duplication issue is addressed through the provision of useful guidelines intended to identify pairs of non-independent criteria. The relative importance (weight) of the individual responses are aggregated by using the individual inconsistencies, knowledge and personal balance of the panel members. The alternative segmentation problem is also discussed and segmentation guidelines based on the project’s functional and geometric characteristics developed. In addition, various geometric restrictions affecting the potential project segmentation are included.
PUBLIC TRANSPORTATION
Assessing the impact of real-time information on transit passenger behavior. Hickman, Mark David, Ph.D. Massachusetts Institute of Technology, 1994. Supervisors: Nigel H.M. Wilson: David H. Bernstein. This thesis develops a modeling framework to examine the impacts of real-time information on transit passenger behavior, particularly the passenger’s choice of path and departure time. By examining how passengers may alter their travel decisions in response to various types of real-time information, the quantitative impacts of passenger information systems can be evaluated. As a foundation for the research, an analytical framework for both transit service and passenger path and departure time choice is presented. A transit service model is developed that explicitly incorporates several elements which most influence the passenger’s trip travel time reliability: stochastic departure and running times, connections between routes, and time-dependence. These elements are critical in examining travel times in a transit network where real-time information may be most useful. Based on these transit service characteristics, two path choice models are developed: a static model, which assumes that the passenger determines a vehicle boarding strategy upon his/her arrival at the origin terminal; and a dynamic model, which assumes that the passenger decides his/her boarding strategy as vehicles arrive at the terminal. The dynamic model is also shown to be
Recent Doctoral Dissertations a right-turn maneuver. Three surveys of driver and pedestrians were conducted to determine their understanding of pertinent laws and traffic control devices. The results indicated that drivers were less likely to know that they must yield to pedestrians when making a left turn. Also, drivers over 75 years of age were found to be significantly less knowledgeable than other age groups about the need to yield the right-of-way to pedestrians when making left or right turns at signalized intersections. Pedestrians’ knowledge of pedestrian signal indications was also evaluated. The results of the survey indicated that pedestrians over 75 years of age were not as aware as younger pedestrians of the potential conflicts with turning vehicles during the Walk indication. Also, pedestrians’ age and knowledge in regard to the flashing Don’t Walk clearance indication were found to be inversely related to each other, with older pedestrians having less understanding of the indication than younger pedestrians.
PRICING
Evaluating the joint implementation of congestion pricing and driver information systems. El Sanhouri, lbrahim Mahmoud, Ph.D. Massachusetts Institute of Technolo~gy, 1994. Supervisor: David H. Bernstein. In this thesis, the joint implementation of congestion pricing and driver information systems is analyzed. After selecting specific pricing and information systems from among the many possible choices based on representativeness and implementability, a modeling framework is developed that analyzes the interaction of the two systems in the presence of incidents, or short-term reductions in network capacity. First, the impact of toll stations is examined by looking at the benefits and costs when stations are either upstream or downstream of the points of congestion. It is found that downstream toll stations distort the arrival times at the toll stations, resulting in toll costs that may be hard to predict. In the upstream case, negative net benefits in costs including tolls were occasionally observed. This occurred when the information system increased the total number of toll paying travelers. Modifying the information systems through reducing guidance rates eliminated or reduced this problem. Two modified pricing systems were also examined. The first consisted of tolls that were Identical across routes for better implementability. A side effect was that revenue-increasing switching was eliminated and negative benefits no longer observed. In the second, only one route was tolled. In that case the optimal route split may not be attainable because Ideally we would like more travelers on the tolled route than is possible .with the restriction on the untolled route. Finally, superadditivity was examined and it is found that for our model, only simple additivity holds. tCopies available exclusively from MIT Libraries, Rm.
14-055 1, Cambridge, MA 02139-4307. 617-253-5668; Fax 617-253-1690.)
Tel.
Quantifying the effects of road pricing on roadway congestion and automobile emissions. Beamon, Benita Michele, Ph.D. Georgia Institute of Technology, 1994. 108 pp. Director: Paul Griffin. Order Number DA9511564 For years, transportation professionals have been engaged in an effort to ease congestion and reduce air pollution on roadways throughout the United States. In spite of these efforts, increasing roadway congestion and poor air quality are facts of life in most urban areas. Increasingly constrained funding for roadway improvement projects, coupled with more stringent environmental legislation, make the task of improving the quality of roadway travel even more difficult. Largely due to these facts, road pricing (direct charges assessed to travelers for use of specific roads during specific time periods) as a method of accomplishing functional and environmental goals, emerges as an attractive alternative worthy of investigation. Although there has been a considerable amount of research on road pricing, there has been little significant progress made in actually quantifying the congestion and environmental effects of such programs. In this research, a model is developed to quantify the reductions in congestion and automobile emissions resulting from two types of road pricing implementations: a Five-Dollar Cordon Scheme and a One-Dollar-Per-Mile Area Link Charging Scheme. The policy issues and possibilities for implementation of road pricing in a democratic society are also investigated. The model results indicate that both schemes are effective at reducing the number of blockages, but only marginally effective at increasing average rush-hour speeds. Both schemes were also found to reduce the amount of automobile emissions of carbon monoxide, nitrous oxides, and hydrocarbons. Except for reductions in nitrous oxides, the Cordon Scheme outperformed the Link Charging Scheme in every other emissions category. Based on these results, a number of recommendations are made which are designed to encourage political acceptability of a road pricing program. Finally, potential areas for future road pricing research are identified.
PROJECT MANAGEMENT
A knowledge-based system approach to work shift selection for multilane highway reconstruction and maintenance projects. Ahmed, Quazi Amin, Ph.D. The University of Florida, 1993. 234 pp. Chairman: Ralph D. Ellis. Order Number DA94-31901
66
Recent Doctoral
The timely, efficient, and quality completion of highway projects partly depends on the selection of the appropriate work shift. Certainly there are advantages and disadvantages for both day and night shifts. Daytime operations are generally considered to be safer for both workers and motorists because of better visibility and a higher state of alertness. However, to accommodate the flow of higher daytime traffic volumes, work zone lane closures may not be possible, and the option to work during the night becomes a serious consideration. A highway project’s characteristics may favor a particular work shift. Type of work, lane capacity, average daily traffic (ADT). work zone accidents, project duration, and project costs are some of the issues that may dictate shift times. This research is aimed towards the development of a decision model that will incorporate all the factors that may influence the selection of either a day or a night work shift. The process is based on a decision tree representing qualitative and quantitative factors, ranked in the order of importance. The shift selection methodology is similar to the human reasoning process and that is why a knowledge-based system approach has been chosen for this decision model. An expert system shell has been utilized to develop the knowledge base, which consists of IF-THEN logic rules. The rule-based knowledge structure also has the option to interface with an external traffic count database for the purpose of lane closure analysis. The model approach to work shift selection includes mathematical reasoning in the analysis of traffic congestion, vehicle accident numbers, motorist (user) costs, and project (owner) costs. The final solution offered by the knowledge-based system model consists of the recommended work shift, number of daytime lane closures allowed, user cost savings for a night shift option, and percent change in total owner cost for a nighttime alternative.
A multicriteria decision-making approach for evaluating alternative transportation plans. Driggs, Raul, Ph.D. Unirrr-sir!: of Miami, 1994. 541 pp. Supervisor: K.G. Zografos. Order Number DA94-26870 The reason for the selection of this particular research topic stems from the perceived need to establish some sort of “standard” to serve as a guide for the professional involved in this type of work at the Project Development and Environment (PD&E) Stage. Potentially inaccurate results are generally derived due to deficiencies in five basic problems areas: (I) lack of clearly defined goals and objectives, (2) absence of weight assignment, (3) lack of sensitivity analysis, (4) criteria duplication, and (5) lack of alternative segmentation. The principal objective of this dissertation is to establish an evaluation methodology that can effectively deal with these five problem areas. Another objective involves the identification of a technique to fairly gauge the relative weight of each
Dissertations
of the judges’ decisions and to properly aggregate the results. A discussion concerning the advantages and disadvantages of various existing multi-objective techniques was conducted. In addition, a panel composed of several PD&E professionals was asked to perform a multi-phase evaluation using various evaluation methodologies. Once a “potential preferred technique” was identified, changes were made to specifically address the five problem areas mentioned above. Finally, a case study intended to test the adequacy of the proposed methodology was conducted. The proposed evaluation methodology promotes the clear definition of goals and objectives by listing up to 147 different criteria normally encountered in transportation projects. The criteria duplication issue is addressed through the provision of useful guidelines intended to identify pairs of non-independent criteria. The relative importance (weight) of the individual responses are aggregated by using the individual inconsistencies, knowledge and personal balance of the panel members. The alternative segmentation problem is also discussed and segmentation guidelines based on the project’s functional and geometric characteristics developed. In addition, various geometric restrictions affecting the potential project segmentation are included.
PUBLIC TRANSPORTATION
Assessing the impact of real-time information on transit passenger behavior. Hickman, Mark David, Ph.D. Massachusetts Institute of Technology, 1994. Supervisors: Nigel H.M. Wilson: David H. Bernstein. This thesis develops a modeling framework to examine the impacts of real-time information on transit passenger behavior, particularly the passenger’s choice of path and departure time. By examining how passengers may alter their travel decisions in response to various types of real-time information, the quantitative impacts of passenger information systems can be evaluated. As a foundation for the research, an analytical framework for both transit service and passenger path and departure time choice is presented. A transit service model is developed that explicitly incorporates several elements which most influence the passenger’s trip travel time reliability: stochastic departure and running times, connections between routes, and time-dependence. These elements are critical in examining travel times in a transit network where real-time information may be most useful. Based on these transit service characteristics, two path choice models are developed: a static model, which assumes that the passenger determines a vehicle boarding strategy upon his/her arrival at the origin terminal; and a dynamic model, which assumes that the passenger decides his/her boarding strategy as vehicles arrive at the terminal. The dynamic model is also shown to be