University of California Transportation Center - 2006-2007 Dissertation Grant Abstracts

UCTC 2008-2009 Dissertation Grant Abstracts

Vehicle Formation Control on Highways

Wenjie Dong, UC Riverside

Advisor: Jay Farrell

In this proposal, we consider vehicle formation control on highways with the aid of local communication between neighbor vehicles. Three control problems are discussed. In the first problem, we discuss the design of decentralized control laws such that a platoon of vehicles cooperatively converges to a stationary formation under various communication scenarios. Dynamic control laws for each vehicle, which are functions of its own state and the relative information about its neighbor vehicles, will be proposed with the aid of sigma-processes and results from graph theory. In the second problem, we discuss the design of decentralized control laws such that a platoon of vehicles converges to and tracks a target point which moves along a desired trajectory under various communication scenarios. In the third problem, we will consider the formation control for multiple vehicles based on output feedback such that a platoon of vehicles converges to and tracks a target point which moves along a desired trajectory. Since communication delay is inevitable in the formation control, in each of the above control problems, we will analyze the effect of delayed communications on the proposed controller performance. To show the effectiveness of the proposed results, computer simulations will be performed.

Key words: Advanced vehicle control systems, intelligent highway systems, formation control, string stability, nonlinear systems, adaptive control.

Developing and testing a methodology for defining pedestrian Quality of Service

Ria Sulinda Hutabarat, UC Berkeley

Advisor: Elizabeth Deakin

Walkability has become a hot topic in the past five years, yet little research has been done to define what it actually means. Various metrics have been put forth as heuristics or aids to planning pedestrian facilities, yet these metrics seem to reflect disciplinary objectives more than research-based knowledge. Many of the metrics lack rigorous, analytical foundations and some are imbued with middle-class, Western values that are far from universal guides to pedestrian planning.

This research extends understanding of walkability by developing a methodology to evaluate operational and design factors that affect the propensity for pedestrians to walk as well as their levels of satisfaction. The research will employ this methodology with statistical procedures to distinguish travel choice preferences of choice (vehicle-owning) and non-choice pedestrians. The methodology involves a mix of qualitative and quantitative methods from travel demand, urban design and ethnographic research.

The research will be conducted in Jakarta – a city characterized by heavy traffic congestion, automobile-oriented transportation infrastructure, high population density and high pedestrian volumes. By undertaking this research in the developing world, it targets conditions for which knowledge gaps are greatest. It also provides an implicit comparison to help distinguish culturally-bound pedestrian values from those that may be more universal preferences.

Key words: Pedestrian transportation, walkability, metrics, urban space, developing world, Jakarta.

Estimating the effects of curb parking prices congestion, air quality and local economic activity

David A. King, UC Los Angeles

Advisor: Donald Shoup

When curb parking spaces are priced below the cost of off-street spaces, drivers have an incentive to cruise for parking. This common situation occurs in nearly all urban commercial districts, creating excess travel by drivers that congests the roads, wastes fuel and increases localized air pollution. Eliminating the excess driving from cruising for parking should be an important local transportation policy goal. To that end, this proposed dissertation will estimate the share of traffic that is cruising for parking in selected commercial districts in Los Angeles. From these estimates, three hypotheses will be tested. First, where curb parking is cheaper than adjacent off-street parking, does an increase in the cost of curb parking up to the price of off-street parking reduce cruising? Second, if cruising is eliminated through increased meter prices, will overall travel to the community decline or is cruising solely excess travel within a commercial district? Lastly, the amount of energy used and air emissions generated by cruising will be estimated. This research contributes to a fuller understanding of how local transportation planning fits into the traditional hierarchal planning approaches. City planners, public officials, traffic engineers and business owners will all benefit from these contributions.

Key words: parking, congestion, air pollution, economics, travel behavior.

Road Safety as a Problem of Framing and Professional Practice

Carolyn McAndrews, UC Berkeley

Advisor: Elizabeth Deakin

Road safety is a serious public health issue throughout the world. In the U.S. motor vehicle crashes were the leading cause of death for people between age five and 34 in 2005, with over 40,000 casualties a year. The record is similar in Mexico, but the overall traffic safety record is far better in many other developed countries with infrastructure, vehicles, and operations similar to those in North America. Among the advanced economies Sweden is often called out as the best performer from a road safety perspective. Why do these differences in safety outcomes persist despite the similarities in technological systems? In my dissertation research I will use a comparative case study design and mixed methods to investigate how road safety professionals (engineers, public health experts, urban planners and designers, law and law enforcement professionals, technology developers) in the U.S., Sweden,and Mexico frame the issue of road safety and how this conceptualization shapes their ability to intervene in the system. I will also conduct a quantitative analysis of system performance with respect to safety for each site as a second point of reference for understanding how road safety poses a challenge for system designers.

Key words: Traffic safety, safety management, frame analysis, comparative planning.

Impact of individual accessibility on travel behavior and its propagation through intra-household interaction

Seo Youn Yoon, UC Santa Barbara

Advisor: Konstadinos Goulias

Accessibility has been considered as an important factor in behavioral decision making. Many studies showed that accessibility does affect behavior patterns such as activity scheduling, destination choice, resource allocation, and activity allocation. In spite of the recognition of the importance of accessibility in behavioral modeling, appropriate accessibility measures based on individual spatio-temporal constraints are rarely used in travel behavior models. This study aims to include accessibility measures as explanatory variables in behavioral models and to assess the relationship between accessibility and behavior especially in the context of intra-household interaction. Group utility functions and structural equations modeling (SEM) were selected as modeling framework for the intra-household interaction. New household utility functions for households with more than two people will be formulated by expanding prototypical models suggested in the most recent household interaction studies. Using SEM, the impact of individual accessibility on behavior patterns will be modeled in a straightforward manner, and also an attempt will be made to build an ultimate model including latent entities in order to better explain the underlying mechanisms in group decision making in households. This measurement and modeling strategies are expected to contribute to the understanding of the relationship between urban development patterns and behavior patterns.

Key words: Individual accessibility, time geography, travel behavior modeling, group decision making, intra-household interaction, household utility, structural equations modeling (SEM).


	UCTC 2008-2009 Dissertation Grant Abstracts Vehicle Formation Control on Highways Wenjie Dong, UC Riverside Advisor: Jay Farrell In this proposal, we consider vehicle formation control on highways with the aid of local communication between neighbor vehicles. Three control problems are discussed. In the first problem, we discuss the design of decentralized control laws such that a platoon of vehicles cooperatively converges to a stationary formation under various communication scenarios. Dynamic control laws for each vehicle, which are functions of its own state and the relative information about its neighbor vehicles, will be proposed with the aid of sigma-processes and results from graph theory. In the second problem, we discuss the design of decentralized control laws such that a platoon of vehicles converges to and tracks a target point which moves along a desired trajectory under various communication scenarios. In the third problem, we will consider the formation control for multiple vehicles based on output feedback such that a platoon of vehicles converges to and tracks a target point which moves along a desired trajectory. Since communication delay is inevitable in the formation control, in each of the above control problems, we will analyze the effect of delayed communications on the proposed controller performance. To show the effectiveness of the proposed results, computer simulations will be performed. Key words: Advanced vehicle control systems, intelligent highway systems, formation control, string stability, nonlinear systems, adaptive control. Developing and testing a methodology for defining pedestrian Quality of Service Ria Sulinda Hutabarat, UC Berkeley Advisor: Elizabeth Deakin Walkability has become a hot topic in the past five years, yet little research has been done to define what it actually means. Various metrics have been put forth as heuristics or aids to planning pedestrian facilities, yet these metrics seem to reflect disciplinary objectives more than research-based knowledge. Many of the metrics lack rigorous, analytical foundations and some are imbued with middle-class, Western values that are far from universal guides to pedestrian planning. This research extends understanding of walkability by developing a methodology to evaluate operational and design factors that affect the propensity for pedestrians to walk as well as their levels of satisfaction. The research will employ this methodology with statistical procedures to distinguish travel choice preferences of choice (vehicle-owning) and non-choice pedestrians. The methodology involves a mix of qualitative and quantitative methods from travel demand, urban design and ethnographic research. The research will be conducted in Jakarta – a city characterized by heavy traffic congestion, automobile-oriented transportation infrastructure, high population density and high pedestrian volumes. By undertaking this research in the developing world, it targets conditions for which knowledge gaps are greatest. It also provides an implicit comparison to help distinguish culturally-bound pedestrian values from those that may be more universal preferences. Key words: Pedestrian transportation, walkability, metrics, urban space, developing world, Jakarta. Estimating the effects of curb parking prices congestion, air quality and local economic activity David A. King, UC Los Angeles Advisor: Donald Shoup When curb parking spaces are priced below the cost of off-street spaces, drivers have an incentive to cruise for parking. This common situation occurs in nearly all urban commercial districts, creating excess travel by drivers that congests the roads, wastes fuel and increases localized air pollution. Eliminating the excess driving from cruising for parking should be an important local transportation policy goal. To that end, this proposed dissertation will estimate the share of traffic that is cruising for parking in selected commercial districts in Los Angeles. From these estimates, three hypotheses will be tested. First, where curb parking is cheaper than adjacent off-street parking, does an increase in the cost of curb parking up to the price of off-street parking reduce cruising? Second, if cruising is eliminated through increased meter prices, will overall travel to the community decline or is cruising solely excess travel within a commercial district? Lastly, the amount of energy used and air emissions generated by cruising will be estimated. This research contributes to a fuller understanding of how local transportation planning fits into the traditional hierarchal planning approaches. City planners, public officials, traffic engineers and business owners will all benefit from these contributions. Key words: parking, congestion, air pollution, economics, travel behavior. Road Safety as a Problem of Framing and Professional Practice Carolyn McAndrews, UC Berkeley Advisor: Elizabeth Deakin Road safety is a serious public health issue throughout the world. In the U.S. motor vehicle crashes were the leading cause of death for people between age five and 34 in 2005, with over 40,000 casualties a year. The record is similar in Mexico, but the overall traffic safety record is far better in many other developed countries with infrastructure, vehicles, and operations similar to those in North America. Among the advanced economies Sweden is often called out as the best performer from a road safety perspective. Why do these differences in safety outcomes persist despite the similarities in technological systems? In my dissertation research I will use a comparative case study design and mixed methods to investigate how road safety professionals (engineers, public health experts, urban planners and designers, law and law enforcement professionals, technology developers) in the U.S., Sweden,and Mexico frame the issue of road safety and how this conceptualization shapes their ability to intervene in the system. I will also conduct a quantitative analysis of system performance with respect to safety for each site as a second point of reference for understanding how road safety poses a challenge for system designers. Key words: Traffic safety, safety management, frame analysis, comparative planning. Impact of individual accessibility on travel behavior and its propagation through intra-household interaction Seo Youn Yoon, UC Santa Barbara Advisor: Konstadinos Goulias Accessibility has been considered as an important factor in behavioral decision making. Many studies showed that accessibility does affect behavior patterns such as activity scheduling, destination choice, resource allocation, and activity allocation. In spite of the recognition of the importance of accessibility in behavioral modeling, appropriate accessibility measures based on individual spatio-temporal constraints are rarely used in travel behavior models. This study aims to include accessibility measures as explanatory variables in behavioral models and to assess the relationship between accessibility and behavior especially in the context of intra-household interaction. Group utility functions and structural equations modeling (SEM) were selected as modeling framework for the intra-household interaction. New household utility functions for households with more than two people will be formulated by expanding prototypical models suggested in the most recent household interaction studies. Using SEM, the impact of individual accessibility on behavior patterns will be modeled in a straightforward manner, and also an attempt will be made to build an ultimate model including latent entities in order to better explain the underlying mechanisms in group decision making in households. This measurement and modeling strategies are expected to contribute to the understanding of the relationship between urban development patterns and behavior patterns. Key words: Individual accessibility, time geography, travel behavior modeling, group decision making, intra-household interaction, household utility, structural equations modeling (SEM).
	©2008 UCTC