Estimating Trip Rates from Traffic Counts

Abstract

The research objective was to utilize routinely collected traffic ground counts to estimate directly area‐wide, all‐purpose trip production rates. The methodology distributes and assigns zonal socio‐economic variables (autos, dwelling units and population) directly to the study area network. Ground counts must be reduced by internal‐external and external‐internal trips. The residual, reduced ground counts are entered into a linear regression model as the dependent variable and the assigned socio‐economic variables are entered as the independent variable. The resulting regression coefficients are estimates of the area‐wide, all‐purpose production rates. The method is sensitive to the friction factor curves used in the distribution step. The methodology was tested in Lynchburg, Virginia and Lexington, Kentucky. Estimated production rates obtained were within 96% of true rates. The method appears to produce accurate results and can be used to verify borrowed production rates in synthetic procedures. It may be useful for cities which cannot undertake conventional household surveys.