GPS-Based Speed Study
Washoe County, Nevada

The Washoe Regional Transportation Commission (RTC) is the metropolitan planning organization for the Reno Metropolitan Area. The Agency selected TJKM to update and revalidate the regional model for use in required planning programs of the agency, including the accurate estimate of speeds for air quality analysis, among other applications. TJKM performed an EMME/2 model update and then provided extensive documentation and training for the RTC staff. TJKM transportation modelers used EMME/2 and TP+ interchangeably for modeling tasks. TJKM developed software that allows modeling software databanks and files to be imported and exported between major modeling platforms including EMME/2, TP+ and TransCAD, leveraging the special capabilities and advantages of each in a given modeling project. This model development required extensive collection of traffic volumes and speeds.

 TJKM performed a countywide GPS-based speed study of auto, truck and bus speeds including GPS data, GIS shape files, data reduction and GIS presentation. The GPS study area involved the entire freeway system and local arterials. It is possible to point to an arterial or freeway segment on the computer monitor and get all relevant traffic data directly and the user can also point to an intersection and get intersection turn counts and model estimates of future turns. Loaded network speeds versus observed speeds are also available. The speeds were used to develop new speed/flow curves for model calibration. Generally, model estimates of current year speeds and volumes are very close to observed values throughout the network. Subsequent to the initial modeling work, the Washoe RTC has continually retained TJKM in modeling enhancement work each year.

Contact Christopher Thnay at cthnay@tjkm.com for information regarding major transportation modeling efforts, including new model development and recalibration/revalidation of existing transportation models.