Completed Projects

(by start year)

2007

Job-Housing Mismatch: An Affinity Model of Worker-Job Matching. Center for Urban and Regional Affairs University of Minnesota.

Cost ~$44,000. Time One year.

Traditionally, travel surveys based on 1% of the population are used to understand travel behavior. Recently, much more complete data has become available to researchers and policy makers, allowing them to better understand job- housing mismatch in a region. The Longitudinal Employer–Household Dynamics dataset, available from the Minnesota Department of Labor, includes residence and employment location information for each employed individual in the Twin Cities metropolitan area (excluding self-employed and selected sales personnel). Using these data, as well as data from other sources, this project will analyze the relationship between people’s choices of residence relative to their employment locations in the Twin Cities region.

This project will extend travel behavior research to help understand the characteristics of people’s choices of residence relative to their employment locations. The central research hypothesis is that although travel time and income are important factors in where people live and work, other factors may help shape the commuting patterns observed in metropolitan areas. Certain residential neighborhoods produce more workers for a given employment district and in a given industrial classification than can be explained by travel time and income alone. By better identifying the causal factors in travel location, travel demand modelers, transportation planners, and engineers will be better able to address job-housing mismatches and imbalances between demand skills and worker skill sets.

2006

Visiting Academic, Dr. Levinson: The Co-Evolution of Transport Networks and Land Use. Economic and Social Research Council
Cost: £89,000. Time: One year.

This project will fund an eminent academic visitor to the UK for one year. Prof. David Levinson, from the University of Minnesota will conduct research on the evolution of transport networks in the UK, such as rail and road networks. This will help us to understand how these networks grow and develop over time. This requires us to understand how travellers and land developers use these networks, both in conducting travel, and in developing the land. This research will build a theoretical and empirical model, using information and data collected in the UK, that will allow us to forecast this growth in the UK. This project will develop a model of the co-evolution of networks and land use, combining what is known about transport demand, and particularly induced demand, and transport investment. This model will provide an understanding of the growth of networks and how these evolve over time.

2005

Access to Destinations: Development of Accessibility Measures. Minnesota Department of Transportation (MNDOT) Transportation systems are designed to help people participate in activities distributed over space and time. Accessibility indicates the collective performance of land use and transportation systems and determines how well that complex system serves its residents. This research project comprises three main tasks. The first task reviews the literature on accessibility and its performance measures with an emphasis on measures that planners and decision makers can understand and replicate. The second task identifies the appropriate measures of accessibility, where accessibility measures are evaluated in terms of ease of understanding, accuracy and complexity, while the third task illustrates these accessibility measures. During this process a new accessibility measure named “Place Rank” is introduced as an accurate measure of accessibility. In addition, several previously-defined accessibility measures are reviewed and demonstrated in this report including Cumulative opportunity and gravity-based measures. The gravity-based measure is widely used in the literature yet cumulative opportunity tends to be easier to understand and interpret by the public, planners, and administrators. A major contribution of this research is the comparison of accessibility measures over time and among various modes. Effects of accessibility on home sales are also tested. Homebuyers pay a premium to live near jobs and away from competing workers. Accessibility promises to be a useful tool for monitoring the land use and transportation system, and assessing and valuing the benefits of proposed changes to either land use or networks.
Cost: $55,000. Time: Two years.

This project reviews the literature on accessibility and its performance measures with an emphasis on measures that planners and decision makers can understand and replicate. It also gauges the appropriate measures of accessibility, while illustrating the accessibility measures.

Metropolitan Travel Survey Archive: Phase 2. Federal Highway Administration Project

This project extended the Metropolitan Travel Survey Archive and enabled online statistical analysis of over 50 travel surveys.

Effectiveness of Learning Transportation Network Growth. University of Minnesota Digital Media Center
Time: One Year

Computer simulation plays an increasingly important role in engineering education as a tool for enhancing classroom learning. This research investigates the efficacy of using simulation in teaching the topic of transportation network growth through an experiment conducted at the Civil Engineering Department of the University of Minnesota. In the experiment, a network growth simulator program (SONG 1.0) was incorporated into a senior/graduate class in transportation system analysis. Results of the experiment show that the use of SONG 1.0 effectively enhanced students learning in terms of helping students develop in-depth understanding about the development process of network patterns, and helped them develop some aspects of judgment, problem-solving, and decision-making skills.

2004

Studying the Needs of the Transportation Disadvantaged: Elderly This project investigates the travel demands and activities (in terms of both actual behavior and unmet needs) of transportation disadvantaged individuals. Broadly, transportation disadvantaged populations include elderly, poor, children, persons who do not speak English, the physically disabled, and the developmentally disabled. To date there has been no comprehensive study of the transportation demands of these disadvantaged populations, who have been ignored in conventional transportation planning. Each group warrants an independent study of significant depth, which is beyond the scope of this single proposal. This first phase of this project will focus on the needs of the elderly and developmentally disabled. and Developmentally Disabled This project investigates the travel demands and activities (in terms of both actual behavior and unmet needs) of transportation disadvantaged individuals. Broadly, transportation disadvantaged populations include elderly, poor, children, persons who do not speak English, the physically disabled, and the developmentally disabled. To date there has been no comprehensive study of the transportation demands of these disadvantaged populations, who have been ignored in conventional transportation planning. Each group warrants an independent study of significant depth, which is beyond the scope of this single proposal. This first phase of this project will focus on the needs of the elderly and developmentally disabled. Cost: $90,000. Time: 18 Months. Hennepin County Project

This project investigates the travel demands and activities (in terms of both actual behavior and unmet needs) of transportation disadvantaged individuals. Broadly, transportation disadvantaged populations include elderly, poor, children, persons who do not speak English, the physically disabled, and the developmentally disabled.

Value of Information for Motorists. MnDOT
Cost: Time: One Years

While there is a sizable body of literature on the benefits of travel information, most of it is based on theory or on simulations. This experiment analyzes results based on a field test of 117 drivers completing the same point-to-point trip in their own vehicles via five different routes. Participants traveled both arterial and freeway routes, assessed the travel information that was provided, evaluated the importance of the accuracy of the information and charted their route preferences for various trip purposes. Researchers were not looking merely for perceived time savings but driver perception of the value of the time saved in order to make projections about whether drivers would be willing to pay for accurate travel updates as a means of reducing overall cost, anxiety and uncertainty while driving. Knowledge of how much users want to pay for Advance Travel Information System (ATIS) services is necessary for the design of sustainable for-profit private services or private/public partnerships.

Benefit-Cost Analysis for Intersection Decision Support. MnDOT

The Intersection Decision Support (IDS) system is designed to assist drivers on stop-controlled low-volume rural roads choosing gaps when confronted with busy multiple lane divided-highways, without affecting traffic on the high-volume road. The hope is, that by providing better gap guidance, fewer crashes (and fatalities) will occur. This research develops a framework for analyzing such a new, and presently under-specified technology, and illustrates that framework by comparing that with more conventional engineering approaches, as well as a “do- nothing” base case. The results show that the IDS System may be an effective tool to reduce crash rates at various intersections. More research is needed to address reliability and stability issues, and in determining how cost- effective of a solution the IDS System is compared to other “traditional” alternatives.

2003

Metropolitan Travel Survey Archive: Phase 1. Bureau of Transportation Statistics

This project developed a Metropolitan Travel Survey Archive to store, preserve, and make publicly available, via the internet, travel surveys conducted by metropolitan areas, states and localities.

Guidelines for Cost-Benefit Analysis of Investment in Bicycle Facilities. National Cooperative Highway Research Program
Cost: $300,000. Time: 18 months.

The focus of this research plan is to develop guidelines to measure the benefits and costs of limited transportation funds in order to achieve four principal objectives:

To compare investments in bicycling with other modes.
To evaluate whether a bicycle facility is justified.
To choose the appropriate bicycle facility.
To better integrate cycling into the general transportation planning process.

2002

Cost/Benefit Study of Spring Load Restrictions. MNDOTThe objective of this study is to determine the economic benefits and costs of spring load restrictions, and based on the findings to determine the optimal restrictions (increases) or heavy load taxes to minimize the combined cost of infrastructure and cost to the industry and commuters. In order to accomplish this objective a number of intermediate objectives are undertaken: Review and synthesize the freeze-thaw effect on material properties and structural capacity to determine how changes in material properties translate into increased/reduced life of pavement; Assign pavement-associated costs/benefits to levels of increased/reduced damage; Determine the demand patterns of large trucks throughout the year; Estimate the value of freight movement on the road network; Estimate the costs of substitute vehicle, routes, modes, schedules; Assign industry associated costs/benefits to various levels of increased/reduced damage; Develop optimal the combination of taxes and restrictions and network improvements
Cost: $300,000. Time: Two years.

The objective of this study is to determine the economic benefit/cost of spring load restrictions, and based on the findings to determine the optimal restrictions (increases) or heavy load taxes to minimize the combined cost of infrastructure and cost to the industry and commuters.

Ramp Delays, Freeway Congestion, and Driver Acceptance. ITS InstituteMinnesota's pre-shutdown ramp metering algorithms tried to maximize throughput, implicitly minimizing total delay. If time at the ramp is not weighted the same as time-in-motion by users, this time-minimizing strategy may not be utility-maximizing for travelers. This research will attempt to quantify the weights individuals associate with qualitatively different experiences of travel time: waiting at a ramp meter or freeway-to-freeway ramp meter and traveling at different freeway speeds requiring varying numbers of acceleration and deceleration shifts, using experiments in the HumanFIRST Driving Simulator. This information will enable us to better time ramp meters in a way that responds to individual perceptions, to maximize utility rather than minimizing travel time.
Cost: $173,265. Time: Two Years

This research quantifies the weights individuals associate with qualitatively different experiences of travel time: waiting at a ramp meter or freeway-to-freeway ramp meter and traveling at different freeway speeds requiring varying numbers of acceleration and deceleration shifts, using experiments in the Human FIRST Driving Simulator. This information enables us to better time ramp meters in a way that responds to individual perceptions, to maximize utility rather than minimizing travel time.

2001

If They Come, Will You Build It. MNDOTThis research will determine the decision rules used by agencies to choose the size of the network relative to demand by examining the actual (revealed) results of what projects are funded. It is hypothesized that simple factors (such as traffic growth rates, volume to capacity ratios, and comparison with adjacent upstream and downstream links) explain much of the resulting decisions. This investigation will examine a time series of local highway capital improvement projects and decisions for the Twin Cities metropolitan region relating them to network structure characteristics. This research will estimate a function that relates capacity to demand factors. Demand will be measured directly using traffic. The term "capacity" is used here broadly to mean a vector of multiple attributes that describe the physical nature of the transportation network. These include the traditional engineering capacity measure (maximum flow per unit time), as well as free-flow speed or travel time, and other attributes.
Cost: $84,546. Time: Two years.

This research will determine the decision rules used by agencies to choose the size of the network relative to demand by examining the actual (revealed) results of what projects are funded. It is hypothesized that simple factors (such as traffic growth rates, volume to capacity ratios, and comparison with adjacent upstream and downstream links) explain much of the resulting decisions.

Value Pricing Project. US Department of Transportation To date, there has been no systematic attempt to examine the relationship between the hierarchy of roads, appropriate level of jurisdiction, and means of financing. Two questions arise from these observations, which must be addressed simultaneously. First, what mechanism is appropriate to finance each different layer of the hierarchy? In some cases, there is competition between links for the same market. In others, a link acts as a monopoly, the only network path between two locations requires the use of a single facility. We may infer that some layers of the hierarchy are more suited to road pricing than others. Further, different types of road pricing (cordon tolls vs. perfect tolls) may be appropriate for different types of roads. Some layers of the hierarchy may warrant subsidy from general tax revenue, while others could be self-supporting with tolls. However, the pool from which this tax revenue is drawn may vary (should it be state, county, township, or neighborhood providing the subsidy), giving rise to the second question. Second, which level of government should manage or regulate which level of the network? There are a number of criteria for dividing the network hierarchically, relating to network function, flow, speed, excludability, competitiveness and alternatives, and locality of traffic. These criteria influence the decision to associate network layers with government layers. An essential issue surrounding hierarchy is the trade-off between span of control and scale economies, including standardization of the finance mechanism. Another is the trade-off between welfare loss associated with lower government levels managing roads that serve in part non-local traffic. Solutions for this problem include hybrid and decentralized organizations and the use of oversight rather than direct management by higher levels of the hierarchy.
(US DOT)Cost: $60,000. Time: Two years.

2000

Sustainable Transportation Applied Research Initiative. Humphrey Institute Project This research endeavors to understand the dynamic growth process of transportation networks at a theoretical and empirical level, recognizing the interdependence of supply and demand, and to develop a model to replicate that process. Key questions examined include: Why do networks expand and contract? How do expectations of the future (forecasts) affect current decisions? Do networks self-organize into hierarchies? What investment rules predict the sequence and location of network improvements? When are already existing facilities expanded (more lanes on the same link) as opposed to new facilities being provided (a new link)? How can transportation planning be improved to take advantage of a new understanding of network dynamics?
Cost: $210,000. Time: Six years.

This research endeavors to understand the dynamic growth process of transportation networks at a theoretical and empirical level, recognizing the interdependence of supply and demand, and to develop a model to replicate that process.

Measuring the Equity and Efficiency of Ramp Meters. MNDOT/International Road Federation The Twin Cities ramp meter system, while successfully increasing the efficiency of freeway traffic flow, has been subject to increased political scrutiny. That scrutiny is due in part to perceptions of inequity in the system. This research analyzed empirical data to assess the pre-October 2000 ramp control strategy and compare it with the “no ramp meter” case on a broad number of criteria. In general metering is efficient for most travelers, but it penalizes those making short trips at the expense of long trips. The research then developed a new ramp control strategy that explicitly addresses both equity and efficiency concerns, and found a strategy that is more efficient than prior strategies, and identified the tradeoff that can be made between efficiency and equity (the most efficient strategy is among the least equitable).
Cost: $161,082. Time: Two Years.

This research analyzed empirical data to assess the pre-October 2000 ramp control strategy and compare it with the “no ramp meter” case on a broad number of criteria. In general metering is efficient for most travelers, but it penalizes those making short trips at the expense of long trips. The research then developed a new ramp control strategy that explicitly addresses both equity and efficiency concerns, and found a strategy that is more efficient than prior strategies, and identified the tradeoff that can be made between efficiency and equity (the most efficient strategy is among the least equitable).

Automated Vehicle Control Algorithms and their Influence on Traffic. ITS instituteAdaptive cruise control (ACC) systems are currently being developed by many automotive manufacturers around the world. These ACC systems will enhance cruise control by adding the ability to automatically maintain a desired spacing with respect to a preceding car that has been detected in the lane. Explicit comparison of two ACC laws, Constant Time Headway (CTH) and Variable Time Headway (VTH), are based on these results. It was found that VTH has better performance in terms of capacity and stability of traffic. Throughput increases with the proportion of CTH vehicles when flow is below capacity conditions. But above capacity, speed variability increases and speed drops with the CTH traffic compared with non-ACC traffic, while the VTH traffic always performs better.
Cost: $184,000. Time: Two years.

This project researches the cruise control systems currently being developed and used by many automotive manufacturers around the world. It focuses on two specific types of Adaptive Cruise Control (ACC).

Improving the Estimation of Travel Demand for Traffic Simulation. ITS instituteTraffic Simulation is only as good as its input data. Unfortunately, it is impossible to inexpensively measure entry ramp to exit ramp flows, which would be particularly useful for testing ramp metering control strategies. In the past, research supported by MnDOT and CTS has produced a viable method for estimating freeway Origin Destination (O-D) patterns from loop detector data. This research will further develop and apply those methods to estimate O-D demand for use in traffic simulation of freeway sections and corridors. We require zone to zone traffic flows from a transportation planning model, and the flows entering (and ideally exiting) on freeway ramps. The objective is to estimate the traffic from each on-ramp to each downstream off-ramp in short time intervals (e.g. 5 min.). This research will include development and implementation of software to enable the method to be used conveniently with easy to collect data. It will then apply the method to selected corridors being analyzed in the Transportation Modeling Laboratory: (TramLab) including I-35W and TH-169.
Cost: $199,763. Time: Two years.

This project estimates origin-destination trip tables from traffic counts.

1998

Evaluation Methods for Measuring the Value of ITS Services and Implementation. California PATH Research Projects
Time: Five Years

As part of my Post Doctorate research, this project was funded through the California Path, and it led to the book: Assessing the Benefits and Costs of Intelligent Transportation Systems.

1994

The Full Cost of Intercity Transportation. California Department of Transportation

This study evaluates the full cost of three modes of intercity transportation: air, highway, and high speed rail. The evaluation is done within the context of the California Corridor, connecting the Los Angeles Basin and the San Francisco Bay Area. The purpose of evaluating full cost is to compare the economic implications of investment in, or expansion of, any of these three modes.