The Vermont Agency of Transportation published the Vermont Trip Generation Manual (Download VermontTripGenerationReportforweb) this year. From the report abstract –
"In reviewing studies for repeated developments in the same area, it has been noted that measures of current traffic do not necessarily show the anticipated level of traffic projected in previous Traffic Impact Studies. Therefore, the purpose of the research reported herein is to measure Trip Generation for the most widely proposed types of development in Vermont and relate it to some measures of the intensity of the particular land uses. The result of this research is this Vermont Trip Generation Manual, to be used in conjunction with the preparation and review of Traffic Impact Studies within the state."
The report is a great example of practical traffic engineering research. They collected data, compared their data to data in the Institute of Transportation Engineers Trip Generation report, and then made recommendations for localized conditions. I really appreciate that they broke their data into rural versus suburban trip generation (not surprisingly, they found rural developments generated less traffic than comparable developments in the suburbs).
Thanks to Jim Sumner from the Vermont Agency of Transportation for sharing the report with me.