Although related in part to employment rates (as the retail uses certainly employ a considerable number of people) the retail component is also related to the residential trip rates, as shopping trips make up a considerable proportion of the typical weekday PM peak hour residential trip generated traffic volumes, often as much as 25%. As such, the retail zones identified within the Town were assessed individually in order to develop reasonable retail trip generation rates for inclusion in the model.
An average trip generation rate of 4.23 trips per 1,000 ft2 was assessed as appropriate based on several retail land use trip generation rates in ITE (including shopping centre, supermarket, home improvement superstore, furniture store, building materials, specialty retail centre, and hardware/ paint store). This trip generation rate was used for existing commercial uses.
It should be noted that developed floor area information was not available at the time of the study, and so the existing retail floor area along Highway 2A was estimated based on developed lot area, adjusted to reflect 10% loss of area due to roads, and with a 25% floor area ratio applied to the remaining area. In the Downtown area, it was assumed that 50% of the Downtown employment was retail in nature, with the remaining 50% office or other.
For the future highway commercial expansions in Transportation Zones 15 and 22 a lower trip generation rate of 2.0 trips per 1,000 ft2 was applied to reflect the expected lower intensity land uses for these areas such as car/RV/tractor dealerships, card lock facilities etc.