Trip Generation at Virginia Agritourism Land Uses

About the report:

When new agritourism land uses are initially proposed, a lack of data on how many vehicle trips these uses tend to create (known as trip generation) means that there is limited guidance available for transportation planners and engineers to make appropriate and sound recommendations regarding entrances and other traffic improvements. Agritourism land uses can include farm wineries, breweries, distilleries, orchards allowing visitors to pick fruits and vegetables, and farm stands and markets. This study reviewed existing information about agritourism trip generation rates and conducted data collection and analysis with regard to these rates at five winery and cidery sites in Virginia. In Virginia, localities have the ability, albeit limited, to regulate special events held at agritourism sites, so this study looked at non-event trip volumes.

Engineers and transportation planners typically use trip generation data from the Institute of Transportation Engineers’ Trip Generation Manual to determine entrance categories and to recommend street improvements and strategies for safety or capacity. The manual includes trip rates for several uses that could be considered related but that do not exactly represent the range or character of agritourism uses, with the possible exception of breweries serving a full menu approximating the manual’s definition of “quality restaurant.” The data reported in the manual for most of these agritourism-related uses had a large degree of variability. Recent studies of trip generation at wineries, all from California, were also reviewed.

Data collected for the five Virginia sites had high variability, but certain independent variables had moderately high correlations with trips: (1) number of employees, (2) population within a 60-minute drive, (3) households within a 60-minute drive, and (4) square footage of tasting room. Although based on a small sample size, the results suggest that established retail wineries/cideries are likely to exceed the Virginia Department of Transportation’s 50-trips-per-day maximum threshold for a “low volume commercial entrance,” falling instead into the “moderate volume commercial entrance” or the “commercial entrance” category.

Based on the findings of this study, it appears that VDOT’s practice of assuming low trip volumes for agritourism land uses may result in entrances that are undersized for the amount of traffic they carry. The “moderate volume commercial entrance” category may be appropriate for agritourism land uses in most cases. In addition, weekday peak hour volumes for the agritourism land use sites studied did not occur during the weekday peak hours of adjacent streets. Promising site-based variables for Virginia wineries include square footage of a tasting room and number of employees at peak season, and when no site-based variables are available other than location, Census-derived variables can provide some information. Additional research could clarify the findings of this study.

Recommendations for VDOT’s Office of Land Use include (1) providing guidance to VDOT’s transportation and land use directors indicating that retail-focused wineries can be assumed to generate well more than 50 vehicle trips per day at peak season and (2) investigating possible adjustments to the traffic volume thresholds for the “moderate volume commercial entrance” category.

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