Day: 2011-10-11

Value of Travel-Time Reliability: Commuters’ Route-Choice Behavior in the Twin Cities

| David Levinson

Recently published: Carrion-Madera, Carlos, David Levinson, and
Kathleen Harder (2011) Value of Travel-Time Reliability: Commuters’ Route-Choice Behavior in the Twin Cities
 (OTREC-RR-11-21):

“Travel-time variability is a noteworthy factor in network performance. It measures the temporal uncertainty experienced by users in their movement between any two nodes in a network. The importance of the time variance depends on the penalties incurred by the users. In road networks, travelers consider the existence of this journey uncertainty in their selection of routes. This choice process takes into account travel-time variability and other characteristics of the travelers and the road network. In this complex behavioral response, a feasible decision is spawned based on not only the amalgamation of attributes, but also on the experience travelers incurred from previous situations. Over the past several years, the analysis of these behavioral responses (travelers’ route choices) to fluctuations in travel-time variability has become a central topic in transportation research. These have generally been based on theoretical approaches built upon Wardropian equilibrium, or empirical formulations using Random Utility Theory. This report focuses on the travel behavior of commuters using Interstate 394 (I-394) and the swapping (bridge) choice behavior of commuters crossing the Mississippi River in Minneapolis. The inferences of this report are based on collected Global Positioning System (GPS) tracking data and accompanying surveys. Furthermore, it also employs two distinct approaches (estimation of Value of Reliability [VOR] and econometric modeling with travelers’ intrapersonal data) in order to analyze the behavioral responses of two distinct sets of subjects in the Minneapolis-Saint Paul (Twin Cities) area.”

Innovation Starvation

| David Levinson

Neal Stephenson on Innovation Starvation :

“… Little has been heard in that vein since. We’ve been talking about wind farms, tidal power, and solar power for decades. Some progress has been made in those areas, but energy is still all about oil. In my city, Seattle, a 35-year-old plan to run a light rail line across Lake Washington is now being blocked by a citizen initiative. Thwarted or endlessly delayed in its efforts to build things, the city plods ahead with a project to paint bicycle lanes on the pavement of thoroughfares.
…
Today’s belief in ineluctable certainty is the true innovation-killer of our age. In this environment, the best an audacious manager can do is to develop small improvements to existing systems—climbing the hill, as it were, toward a local maximum, trimming fat, eking out the occasional tiny innovation—like city planners painting bicycle lanes on the streets as a gesture toward solving our energy problems. Any strategy that involves crossing a valley—accepting short-term losses to reach a higher hill in the distance—will soon be brought to a halt by the demands of a system that celebrates short-term gains and tolerates stagnation, but condemns anything else as failure. In short, a world where big stuff can never get done. …”