Category Archives: working papers

Accessibility and the Allocation of Time: Changes in Travel Behavior 1990-2010

Congratulations to Martin Brosnan for successfully completing his MS Thesis: Accessibility and the Allocation of Time: Changes in Travel Behavior 1990-2010. He is now a consultant with CDM Smith in Illinois.

Martin Brosnan
Martin Brosnan

Using detailed travel surveys conducted by the Metropolitan Council of the Minneapolis/Saint Paul region for 1990, 2000-2001, and 2010-2011, this study analyses journey-to- work times, activity allocation and accessibility. The analysis shows a decline in the time people spend outside of their homes as well as the time people spend in travel over the past decade. Although distances per trip are increasing, the willingness to make trips is declining, resulting in fewer kilometers traveled and less time allocated to travel. This study finds accessibility to be a significant factor in commute durations. Accessibility and commute duration have large effects on the amount of time spent at work therefore activity patterns are influenced by transportation and the urban environment.

Accessibility and the choice of network investments in the London Underground

Congratulations to David Giacomin for completing his MS Thesis: Accessibility and the choice of network investments in the London Underground. He is now a consultant for Kimley-Horn in Nevada.

David Giacomin
David Giacomin

 

In 1863, the Metropolitan Railway of what came to be known as the London Underground successfully opened as the world’s first subway. Its high ridership spawned interest in additional links. Entrepreneurs secured funding and then proposed new lines to Parliament for approval, though only a portion were actually approved. While putative rail barons may have conducted some economic analysis, the final decision lay with Parliament, which did not have available modern transportation economic or geographic analysis tools. How good were the decisions that Parliament made in approving Underground Lines? This paper explores the role accessibility played on the decision to approve or reject proposed early London Tube Schemes.

Indifference Bands for Route Switching

Recent working paper:

Di, X, Liu, H, Zhu, S, and Levinson, D. (2014) Indifference Bands for Route Switching

Frequency of Switchers and Stayers vs. Travel Time Saving Percentage
Frequency of Switchers and Stayers vs. Travel Time Saving Percentage
  • Abstract: The replacement I-35W bridge in Minneapolis saw less traffic than the original bridge though it provided substantial travel time saving for many travelers. This observation cannot be explained by the classical route choice assumption that travelers always take the shortest path. Accordingly, a boundedly rational route switching model is proposed assuming that travelers will not switch to the new bridge unless travel time saving goes beyond a threshold or “indifference band”. To validate the boundedly rational route switching assumption, route choices of 78 subjects from a GPS travel behavior study were analyzed before and after the addition of the new I-35W bridge. Indifference bands are estimated for both commuters who were previously bridge users and those who never had the experience of using the old bridge. This study offers the first empirical estimation of bounded rationality parameters from GPS data and provides guidelines for traffic assignment.
    Keywords: Route Choice, Travel Demand Modeling, Bounded Rationality, Indifference Band, GPS Study, Travel Behavior, Networks

Alternative High Occupancy/Toll Lane Pricing Strategies and their Effect on Market Share

Recent working paper:

Janson, M. and Levinson, D. (2014) Alternative High Occupancy/Toll Lane Pricing Strategies and their Effect on Market Share

Price vs. Density
Price vs. Density
  • High Occupancy/Toll (HOT) Lanes typically charge a varying to single occupant vehicles (SOVs), with the toll increasing during more congested periods. The toll is usually tied to time of day or to the density of vehicles in the HOT lane. The purpose of raising the toll with congestion is to discourage demand enough to maintain a high level of service (LOS) in the HOT lane. Janson and Levinson (2014) demonstrated that the HOT toll may act as a signal of downstream congestion (in both general purpose (GP) and HOT lanes), causing an increase in demand for the HOT lane, at least at lower prices. This paper builds off that research and explores alternative HOT lane pricing strategies, including the use of GP density as a factor in price to more accurately reflect the value of the HOT lane. In addition, the paper explores the potential effect these strategies would have on the HOT lane vehicle share through a partial equilibrium analysis. This analysis demonstrates the change in demand elasticity with price, showing the point at which drivers switch from a positive to negative elasticity.

Accessibility and the choice of network investments in the London Underground

Recent working paper:

Levinson, D., Giacomin, D., and Badsey-Ellis, A. (2014) Accessibility and the choice of network investments in the London Underground. Presented at the World Symposium on Transport and Land Use Research, June 2014, at Delft.

Accessibility in London in 1881
Accessibility in London in 1881

 

 

  • Abstract: In 1863, the Metropolitan Railway of what came to be known as the London Underground successfully opened as the world’s first subway. Its high ridership spawned interest in additional links. Entrepreneurs secured funding and then proposed new lines to Parliament for approval, though only a portion were actually approved. While putative rail barons may have conducted some economic analysis, the final decision lay with Parliament, which did not have available modern transportation economic or geographic analysis tools. How good were the decisions that Parliament made in approving Underground Lines? This paper explores the role accessibility played on the decision to approve or reject proposed early London Tube Schemes. It finds that maximizing accessibility to population (highly correlated with revenue and ridership) largely explains Parliamentary approvals and rejections.
    Keywords: Accessibility, Network Growth, Subways, Public Transport, Travel Behavior, Networks

Developing a Comprehensive US Transit Accessibility Database

Recent working paper:

Transit Accessibility in Minneapolis
Transit Accessibility in Minneapolis

Owen, A. and Levinson, D. (2014) Developing a Comprehensive US Transit Accessibility Database

  • This paper discusses the development of a national public transit accessibility evaluation framework, focusing on lessons learned, data source evaluation and selection, calculation methodology, and examples of accessibility evaluation results. In both practice and in research, accessibility evaluation remains experimental and methodologically fragmented. This heightens the “first mover” risk for agencies seeking to implement accessibility-based planning practices, as they must select a method which might produce results that can only be interpreted locally. Development of a common baseline accessibility metric could advance the use of accessibility- based planning. The accessibility evaluation framework described here builds on methods developed in earlier project, extended for use on a national scale and at the Census block level. Application on a national scale involves assembling and processing a comprehensive national database of public transit network topology and travel times. This database incorporates the significant computational advancement of calculating accessibility continuously for every minute within a departure time window of interest. Values for contiguous departure time spans can then be averaged or analyzed for variance over time. This significantly increases computational complexity, but provides a very robust representation of the interaction between transit service frequency and accessibility at multiple departure times.

HOT or not: Driver elasticity to price on the MnPASS HOT lanes

Recently published:

  • I-394 MnPass Map
    I-394 MnPass Map

    Janson, M. and Levinson, D. (2014) HOT or not: Driver elasticity to price on the MnPASS HOT lanes. Research in Transportation Economics. [doi] (preprint)

    The Minnesota Department of Transportation (MnDOT) has added MnPASS High Occupancy Toll (HOT) lanes on two freeway corridors in the Twin Cities. While not the first HOT lanes in the country, the MnPASS lanes are the first implementation of road pricing in Minnesota and possess a dynamic pricing schedule. Tolls charged to single occupant vehicles (SOVs) are adjusted every 3 min according to HOT lane vehicle density. Given the infancy of systems like MnPASS, questions remain about drivers’ responses to toll prices. Three field experiments were conducted on the corridors during which prices were changed. Data from the field experiments as well as two years of toll and traffic data were analyzed to measure driver responses to pricing changes. Driver elasticity to price was positive with magnitudes less than 1.0. This positive relationship between price and demand is in contrast with the previously held belief that raising the price would discourage demand. In addition, drivers consistently paid between approximately $60–120 per hour of travel time savings, much higher than the average value of time. Reasons for these results is discussed as well as the implications these results have on the pricing of HOT lanes.

    Keywords
    Road pricing; Toll roads; Demand elasticity; High-occupancy toll lanes; Managed lanes; High-occupancy vehicles