Impact of Data Source on Travel Time Reliability Assessment Impact of Data Source on Travel Time Reliability Assessment Final Project report Mid-Atlantic Universities Transportation Center Title and Subtitle: Impact of Data Source on Travel Time Reliabili

Travel time reliability measures are becoming an increasingly important input to the mobility and congestion management studies. In the case of Maryland State Highway Administration, reliability measures are key elements in the agency's Annual Mobility Report that is used for both transportation planning and operations. Recent advancements in vehicle tracking technologies have provided both private sectors and transportation agencies with multiple technologies for travel time data collection. This paper investigates the effect of data source selection on travel time reliability assessment. One year data from two independent sources, probe and Bluetooth, on two major freeway corridors in Maryland are used for travel time reliability analysis. Bluetooth sensors are permanently installed on multiple points of these two corridors and probe data are provided by INRIX. A statistical method is applied to compare reliability measures obtained from both sources. Several travel time reliability performance measures are studied. Results show that some reliability measures are more sensitive to the data source than the others. It is also shown that performance measures for HOV and general purpose lanes must be calculated separately