SPC Logo Congestion Management Process

Congestion Management
System Definition
Performance Measures
Technical Notes
Performance Monitoring/Data
Regional Ratings
Regional CMP Map
Allegheny Co. Corridors
-- Pittsburgh Corridors
-- Downtown Pgh Corridors
Armstrong Co. Corridors
Beaver Co. Corridors
Butler Co. Corridors
Fayette Co. Corridors
Greene Co. Corridors
Indiana Co. Corridors
Lawrence Co. Corridors
Washington Co. Corridors
Westmoreland Co. Corridors
Congestion Management Strategies
Evaluating Congestion Mitigation Strategies
Strategy Implementation & Monitoring Effectiveness

Questions or concerns about the Congestion Management ProcessData Library? Please contact:

Domenic D'Andrea
(412) 391-5590 x341


[ close window ]
  Congestion Management Process


What is congestion?

Virtually everyone who has ever traveled America’s roadways, whether it be in their own personal automobile, on a bus, or behind the wheel of a big rig, has had the experience of sitting in traffic.  Congestion is the level at which transportation system performance is no longer acceptable due to traffic interference. The level of acceptable performance can vary by the type of transportation facility, by location within the region, and by time of day. For instance, commuters typically expect and are generally willing to accept a certain amount of traffic during morning and evening “rush hours”. However, they may not be willing to accept that same level of performance in the middle of the day.

In general, highway congestion results when traffic demand approaches or exceeds the available capacity of the highway system. The level of traffic demand can vary significantly depending on the season, the day of the week, and the time of day. Also, the capacity of the highway system, which is usually thought of as constant, can change because of weather, work zones, traffic incidents, or other non-recurring events.

Photo Of Traffic Congestion In Monroeville, Allegheny County

What is a Congestion Management Process (CMP)?

Federal transportation legislation requires that each metropolitan planning area in the United States have what is called a Congestion Management Process, or CMP.  The CMP is a regional program to address and manage congestion within the 10-county Southwestern Pennsylvania region in order to facilitate the movement of people and goods.

The CMP is a broad, regional level planning tool designed to help manage congestion by identifying congested corridors and recommending multimodal strategies for congestion mitigation. The goal of the CMP is to provide information that helps transportation planners, professionals and others to understand the overall congestion climate in individual corridors and the region. Data on the congestion climate helps SPC, in partnership with other agencies, to formulate congestion management strategies. Data and information from the CMP benefits the transportation planning process by helping the region focus limited federal transportation dollars where they can have the greatest impact.


New, emerging technologies such as Bluetooth and INRIX data collection have simplified SPC’s data collection for CMP corridors.  For more information, see the Performance Measures page.

CMP Diagram

[ top ]

[ close window ]