GPS travel data collected as part of a regional or statewide household travel survey (HTS) can provide an alternative source of transportation system performance data. GPS data from HTSs are typically used for trip rate validation and for populating baseline network attributes. However, these GPS data can also be used for other transportation planning purposes. A key value to this type of data is that it is generated from a known demographic and geographic-based sample. This allows observed delays and network performance to be connected back to specific segments of the population. Further, the GPS data is detailed enough to identify time-of-day specific travel experiences such as turning delays, short traffic stops, queuing, and high variability in travel speeds. Other data sources, such as sensor-based monitoring systems and cell phone data systems, typically reveal system performance for a region’s major transportation facilities. However, smaller-scale issues are not typically covered in these regional performance datasets, in modeling capabilities, or in practice.
To demonstrate this capability, GPS travel data from the 2011 Atlanta Regional Commission’s Household Travel Survey was linked to the region’s road network to measure household and facility-level travel delays. Results were then analyzed to identify the times-of-day, locations, and extents of travel delay by mode, movement, facility, and household demographic. These results are providing planners with new information regarding community need and opportunities for maintenance and operational investment at a time when capital investments are difficult to finance. This detailed information can then be used to target small-scale operational improvements that may not be evident in traditional post-survey models or congestion management programs.