Document Type

Journal Article

Publication Date


Subject Area

operations - traffic


Trip purpose, Trip generation, Traffic generation, Traffic counts, Traffic census, Peak periods, Mixed use development, Joint occupancy of buildings, Estimating, Driveways


A study is reported which counted trips at driveways serving existing mixed-use developments in Colorado. 24-hour counts were obtained at each driveway serving the mixed-use developments. These data were then compared with trip generation estimates based on ITE (Institute of Transportation Engineers) rates and modified by the methodology described in "Using the ITE Trip Generation Report." Interviews were also conducted of persons entering and exiting mixed-use sites to determine whether they had come for multiple purposes. Details of the study methodology are described, and the study results are tabulated and discussed. It was found that the total daily trips generated by a mixed-use site can be accurately estimated using ITE rates. Peak-hour trip generation for a mixed-use development based on ITE rates applied to individual uses within the development may be overestimated by an average 2.5%. It was also found that 77% of the persons entering a mixed-use site were there for one purpose, and that mixed-use developments could reduce trip generation of individual uses within the development by 25%. Recommendations resulting from the study are presented.