TITLE:
Evaluation of the Accuracy and Automation of Travel Time and Delay Data Collection Methods
AUTHORS:
Robert Suarez, Ardeshir Faghri, Mingxin Li
KEYWORDS:
Travel Time and Delay; Data Collection; Accuracy and Automation; GPS
JOURNAL NAME:
Journal of Transportation Technologies,
Vol.4 No.1,
January
23,
2014
ABSTRACT: Travel time and delay are among the most important measures
for gauging a transportation system’s performance. To address the
growing problem of congestion in the US, transportation planning legislation
mandated the monitoring and analysis of system performance and produced a
renewed interest in travel time and delay studies. The use of
traditional sensors installed on major roads (e.g. inductive loops) for
collecting data is necessary but not sufficient because of their limited
coverage and expensive costs for setting up and maintaining the required
infrastructure. The GPS-based techniques employed by the University of Delaware have evolved
into an automated system, which provides more realistic
experience of a traffic flow throughout the road links. However,
human error and the weaknesses of using GPS devices in urban settings still have
the potential to create inaccuracies. By simultaneously collecting data using
three different techniques, the accuracy of the GPS positioning data and the
resulting travel time and delay values could be objectively compared for
automation and statistically compared for accuracy. It was found that
the new technique provided the greatest automation requiring minimal attention
of the data collectors and automatically processing the data sets. The data
samples were statistically analyzed by using a combination of parametric and
nonparametric statistical tests. This analysis greatly favored the GeoStats GPS
method over the rest methods.