A preliminary plan of subdivision must be accompanied by a traffic
impact study if the proposed development generates 50 trips or more
during any peak hour. Traffic studies for proposed developments of this
size or larger are prepared by the applicant and reviewed by staff in
order for the Planning Board to make the required findings regarding
adequacy of transportation facilities in the Subdivision Ordinance. In
cases where a development generates fewer than 50 trips, the
transportation staff must still review the preliminary plan in order for
the Planning Board to make the required findings, and may request (but
not require) a limited traffic study or traffic counts to assist in
making these findings. Developments generating five or fewer peak hour
trips may be deemed to have a minimal, or de minimus, impact, and if so
deemed, are not required to provide traffic-related information.
Traffic is also reviewed in detail during review of mixed-use and comprehensive design rezoning applications. Certain types of special exceptions require limited traffic analyses, but in accordance with the required special exception findings, such studies often focus on traffic safety. As noted earlier, detailed site plans are intended to review design issues, and as such generally do not involve the review of transportation adequacy issues.