Subdivision Staging Policy Community Workshop Glossary and Background Information

Adequate Public Facilities Ordinance (APFO): A County ordinance requiring a determination that public facilities are adequate to accommodate growth resulting from approval of a subdivision application.

Cluster: A school cluster is defined by an individual high school and consists of the elementary and middle schools that feed into that high school.  There are currently 25 clusters within Montgomery County.

Critical Lane Volume (CLV): The sum of traffic volumes that cross at a single point in an intersection. The resulting product is used to determine the level of service of an intersection in a Local Area Transportation Review (LATR).

Impact Tax: A charge collected by the Montgomery County Department of Permitting Services to help pay the costs of providing public facilities in designated areas. The tax is generally collected at the time of building permit.

Local Area Transportation Review (LATR): Part of the Adequate Public Facilities test used to determine if a proposed development will produce detrimental traffic impacts that go beyond the capacity of existing and programmed roadways and intersections in the vicinity of the site.

Mitigation: Strategies designed to address travel demand when projected traffic generated from proposed development projects exceeds the applicable policy area congestion standard.  In order of priority for application, these strategies are:

  • Transportation demand management (TDM) approached to reduce vehicular demand;
  • Pedestrian or bicycle improvements;
  • Transit facility of service improvements;
  • Intersection operational improvements; and
  • Roadway capacity improvements.

Moderately Priced Dwelling Unit (MPDU) Program: First implemented in Montgomery County, Maryland in the early 1970s, an inclusionary zoning/affordable housing program requiring a certain percentage of housing units built in residential developments of 20 units or more be affordable, i.e. capable of being purchased or rented by those making less than the County’s median income. (Codified in Chapter 25A of the Montgomery County code).

Moratoria: A temporary halt on approval of new residential development applications that occurs when capacity utilization in a school or cluster meets certain thresholds.  When an area is in moratorium, previously approved projects can continue to move forward.   The moratorium thresholds are as follows:

Test Level Moratorium Threshold
Cluster Projected cumulative utilization greater than 120% at any school level (elementary, middle or high school) across the entire cluster.
Individual Elementary School Projected utilization greater than 120% and projected capacity deficit of 110 seats or more.
Individual Middle School Projected utilization greater than 120% and projected capacity deficit of 180 seats or more.


Policy Area: A geographic sub-area of the County delineated by the Planning Board and adopted by the County Council in the Subdivision Staging Policy for the purpose of staging analysis and the establishment of transportation staging ceiling capacities.

Policy Area Test: Transportation adequacy tests previously contained within the Subdivision Staging Policy that measured levels of service our transportation network to help determine an appropriate rate and level of growth for a policy area.

Preliminary Plan: A plan for a proposed subdivision or resubdivision of land submitted under Chapter 50, Subdivision, of the Montgomery County Code. The plan is reviewed by staff and submitted for action (approval or disapproval) by the Montgomery County Planning Board. Board approval of the plan is necessary prior to preparation of a record plat.

School Facility Payment: An additional per unit fee previously charged to developers when projected cluster utilization exceeded 105%.

Schools Test: The Annual Schools Test results determine if and when new residential subdivisions in any school service area should be subject to a development moratorium based on the projected utilization of school facilities. Projected utilization is based on enrollment and capacity five years into the future.

Student Generation Rate (SGR): A ratio calculating the average number of students per dwelling unit.

Subdivision Staging Policy: The purpose of the Subdivision Staging Policy is to establish a process that can give guidance on matters concerning land use development, growth management, and related issues. It includes guidelines for the Planning Board and other agencies in administering laws and regulations that affect the adequacy and timing of public facilities needed to support growth and development and is to be adopted by the Council every four years.

Transportation Demand Management (TDM): A range of programs and services designed to reduce the use of single-occupant vehicle trips, particularly during periods of peak travel. TDM strategies provide travel options that reduce and spread demand by travel destination, mode, route, and time of day to most efficiently use transportation system infrastructure and resources.

Unified Mobility Program (UMP): A program to calculate the costs associated with transportation facilities (including roads, sidewalks, bikeways, transit) needed to adequately support the development potential prescribed in a master plan; and, the formulation of a pro-rata share to be charged of each developer at time of development.

Utilization: Capacity utilization is the ratio between a school’s enrollment and capacity.  A school with a capacity utilization of 120% means that its enrollment exceeds the school’s capacity by 20%.

Vision Zero: Montgomery County’s initiative to eliminate severe injuries and fatalities on our roads by 2030.  The effort is premised on several principles, including the idea that transportation-related deaths and severe injuries are preventable, that human life takes priority over mobility and other objectives of the road system, and that human error is inevitable and therefore our transportation system should be designed to anticipate such error.

Last Updated: October 30, 2019