Urban Travel Forecasting (167-9F)

Study Number 2-10-71-167, entitled "Urban Travel Forecasting," was a 3-year planning study directed toward providing continuing technical support to the Texas Highway Department in the conduct of urban transportation studies throughout the State. Under this study, assistance was provided in the analysis and forecasting techniques relative to urban transportation studies; the maintenance and modification of computer programs previously developed for and used by the Texas Highway Department; the preparation of additional computer programs; and the implementation of research findings and the use of models and computer programs developed under this study or its predecessors (i.e., Studies 2-8-63-60 and 2-10-68-119).|The accuracy of home interview data in estimating zonal trip ends and travel patterns was investigated using 100% survey data from 3 zones. These analyses indicated disturbingly low probabilities of reasonably accurate estimates of either zonal trip ends or travel patterns using traditional sampling rates. These analyses suggest, however, that an estimating equation (regression model or cross-classification rates) based on either disaggregate or aggregate data will provide more reliable estimates of zonal trip ends than the O-D survey directly. These analyses also indicated that significant cost savings could be achieved while still maintaining acceptable accuracy of trip generation estimates through more statistically efficient procedures and the knowledge of experienced analysts. Based largely on these findings, a synthetic study was proposed, designed, and implemented in a cooperative effort between the Texas Highway Department and Texas Transportation Institute. A preliminary macroscopic analysis of the temporary stability of trip generation rates indicates that these rates have been increasing as a result of a greater propensity to travel and changes in socioeconomic characteristics.|A preliminary evaluation of induced traffic on new highway facilities suggests that this element may account for a significant portion of the traffic on many new facilities and may partially explain the tendency to underestimate traffic on such facilities.