Forecasting Travel Time Variability in Urban Areas

Executive summary

Recent years have seen a growing interest in monitoring travel time variability (TTV) on the highway network and developing methods to forecast TTV. This series of reports describes work currently (2008) being undertaken for the UK Department for Transport to develop methods for calculating and forecasting TTV using data collected from Global Positioning System (GPS) tracker-equipped vehicles. Primary data on vehicle location and time can be transformed into data on times taken to traverse different links on the road network. A database has been constructed comprising travel times for individual vehicles on 34 routes (up to 12km long) within the 10 largest urban areas in England for a period of 3 years. This database of individual vehicles has been used to construct a TTV database containing data on the standard deviation of travel time along individual links in these routes as well as journeys comprising more than one consecutive links.

Deliverable D1: Data Analysis and Model Development (2 Mb)

This first report describes the quality of the GPS database and its usefulness for monitoring TTV, followed by indications of appropriate relationships that can be used to predict TTV in urban areas.

Published:

22 May 2008

Last update:

01 October 2008

Deliverable D2: Model Application (2 Mb)

The second report describes the application of the recommended model to recently appraised urban highway schemes in order to assess the potential impact of including TTV within an economic appraisal. It describes the selected schemes and data requirements and methodologies used during the application phase. It also discusses the TTV model results and issues relating to wider implementation of TTV appraisals.

Published:

17 November 2008