Access to Destinations: Arterial Data Acquisition and Network-Wide Travel Time Estimation (Phase III)

Project summary:

This work is a continuation of the project on the arterial travel time estimation, Phases I and II. In Phase I, a suite of link performance functions based on the demand flow, traffic control and geometric characteristics was developed and evaluated. The expectation is that the recommended performance functions will produce plausible default estimates of travel times when given predicted flows, and that these can be updated where and when field measurements are available.

In Phase II, field measurement data such as traffic volumes, speeds, and traffic control plans were acquired and a relational database was partially constructed through the integration of appropriate Geographical Information System (GIS). The prime objective of Phase II was to not only compute default estimates of arterial travel times on all Twin Cities arterial links by applying the methods developed in Phase I, but to update these default estimates using the collected traffic data, and incorporate these into the GIS-based relational database.

Phase II has encountered several roadblocks, most of them related to the availability and quality of the signal location and timing information from the different jurisdictions in the Twin Cities metro area. Although Phase II will reach its objective, further discussions relating this effort with the greater Access to Destinations program framework revealed the necessity for streamlining the production of link travel times in order to supply estimates for more years than 1995 and 2005, which were the objective of Phase II.

In what is likely to be an enduring period of constrained public resources, lawmakers and government executives will seek the best information possible for making policy choices and deciding where to make public investments. In a landmark series of studies known as Access to Destinations, the Center for Transportation Studies (CTS) at the University of Minnesota has opened up new frontiers of information for better policy and investment decisions.