Day: 2011-04-22

Predictable Bicycle Tragedy Points to Need for New Street Priorities at University of Minnesota

| David Levinson

twin city sidewalks writes: Predictable Bicycle Tragedy Points to Need for New Street Priorities at University of Minnesota: “To put it bluntly, much of the the street design at University of Minnesota makes it almost inevitable that pedestrians and cyclists will be killed.
“

This is the second pedestrian/bicyclist death in Dinkytown in less than a week, though the other was hit-and-run driver running onto the sidewalk.
Obviously the driver is at fault. The question the community needs to ask is could street design have something to do with bad driving? Or, is a one-way pair appropriate here (University/Fourth)? Sure it is great to evacuate the arenas and stadium after a game, but it is an inherent conflict with the more common daily activities on the route. Getting the through vehicle traffic away from local non-motorized campus traffic should be a strategy considered. (e.g. Suppose Granary Road were to be completed instead of just discussed).

Traveler delay costs and value of time with trip chains, flexible activity scheduling and information

| David Levinson

Jenelius-Graph
Recently published:

Abstract: The delay costs of traffic disruptions and congestion and the value of travel time reliability are typically evaluated using single trip scheduling models, which treat the trip in isolation of previous and subsequent trips and activities. In practice, however, when activity scheduling to some extent is flexible, the impact of delay on one trip will depend on the actual and predicted travel time on itself as well as other trips, which is important to consider for long-lasting disturbances and when assessing the value of travel information. In this paper we extend the single trip approach into a two trips chain and activity scheduling model. Preferences are represented as marginal activity utility functions that take scheduling flexibility into account. We analytically derive trip timing optimality conditions, the value of travel time and schedule adjustments in response to travel time increases. We show how the single trip models are special cases of the present model and can be generalized to a setting with trip chains and flexible scheduling. We investigate numerically how the delay cost depends on the delay duration and its distribution on different trips during the day, the accuracy of delay prediction and travel information, and the scheduling flexibility of work hours. The extension of the model framework to more complex schedules is discussed.

Research highlights:

  • Extends single-trip modeling approach for value of reliability and delay costs.
  • Trip chain and activities model with scheduling flexibility.
  • Derives values of travel time and schedule adjustments in response to journey delay.
  • Shows single trip scheduling models are special cases.
  • Handles imperfect delay prediction, information and long-lasting disruptions.

Keywords:Congestion; Disruption; Delay cost; Reliability; Schedule; Value of time

Access Minnesota | Fix It First – Changing the Way We Maintain & Pay For Highways

| David Levinson

I was interviewed on radio by Access Minnesota talking about Fix It First – Changing the Way We Maintain & Pay For Highways

(based in part on the paper Matt Kahn and I wrote).

For the week of April 3rd, 2011

Guest: David Levinson, associate professor in the Department of Civil Engineering at the University of Minnesota

Issues: How we pay for roads; What’s wrong with the way we build and maintain our infrastructure and why; Opportunities for reforming distribution in Congress; Funding options through tolls and user fees; Sacrifices of repair instead of adding capacity; Building better roads to save money in the long term

Download interview