Survey and Model Development of Commercial Vehicles in Dallas-Fort Worth Metroplex
Corresponding Author: zhen ding, North Central Texas Council of Governments
Presented By: zhen ding, North Central Texas Council of Governments
This paper covers two related topics. The first part introduces the commercial vehicle survey (CVS) conducted in the Dallas-Fort Worth (DFW) metropolitan area in 2012. The second part describes the development of a commercial vehicle model (CVM) for the DFW region based on the CVS.
The 2012 CVS was a combined effort of the Texas Department of Transportation (TxDOT), Texas A&M Transportation Institute (TTI), and North Central Texas Council of Government (NCTCOG). By definition, commercial vehicles (CV) not only include freight transporting trucks but also any commercial service vehicles including cars, vans, or pickup trucks. A commercial vehicle trip is any work-related trip other than a commuting trip. The survey collected characteristics of CV trips including trip rate, trip length, stop pattern, and vehicle type. The CVS also assembled information including business type, employment size, and fleet size from the businesses that operate CVs. The categorical definition of the CVS included five business types (basic, retail, service, education, and transportation), three employment sizes, and three CV types (light, medium, and heavy). The survey was completed by 997 businesses that own CVs, and included 1,434 CV trip diaries. The survey demonstrated unique characteristics of CV travel that is different from regular vehicle trips.
With the CV trip rates estimated based on the 2012 CVS, a multiple class commercial vehicle model was developed for Dallas-Fort Worth region. In order to reflect the CV travel characteristics at both origin and destination, the trip rates for commercial trip production and attraction were estimated respectively within dimensions of three business types and three vehicle classifications. According to the base year (2012) forecasts of the CV model, there are about 3.3 million daily CV trips.
For the trip distribution, a gravity model was developed and calibrated by a sparse production-attraction (PA) matrix extracted from the CVS. The CV model validation showed that the CV trip length distribution adequately matched that of CVS actual trips. Overall comparison of the traffic assignment results and the actual counts indicated a reasonable match without apparent bias.