Are we there yet? Smart growth, travel forecasting, and transportation adequacy in Montgomery County, Maryland

Montgomery County, Maryland has an Adequate Public Facilities Ordinance (APFO) that requires the county’s Planning Board to determine that available or programmed transportation facilities can accommodate the peak-period trips that a proposed residential or commercial subdivision will generate before they can approve that subdivision. This requirement generates nearly continuous discussion among policy makers, residents, property developers, and other interest groups about what it means for a transportation system to be adequate. Since 2007, the county’s biennial growth policy has addressed that issue with a measure called Policy Area Mobility Review (PAMR). The review uses a regional travel-demand model to consider current and future system performance across 32 policy areas that range in size from ten to thirty square miles. The PAMR analysis integrates transit system and roadway system mobility measures, incorporating a county policy that transportation-system equity can be maintained by allowing more congestion in areas with better transit service. The regional nature of the PAMR analysis provides geographic and analytic capabilities beyond the typical traffic-impact study. The Montgomery County Planning Board (MCPB) uses PAMR for both near-term subdivision regulation for compliance with the APFO and long-term master-planning purposes. These characteristics of the PAMR application, plus context-sensitive development-mitigation approaches including peak-hour vehicle trip-reduction measures, additional public transit capacity, and nonautomobile-transportation facilities, help improve the sustainability of new development. This article describes how PAMR has worked and the issues its use has generated in integrating sustainability into the transportation-planning process.