Major CMP Components

Monitoring and Evaluating Transportation System Performance

Freeway Monitoring Program

Freeways comprise the critical backbone of the region's roadway system, and provide the most important indicator of our overall system. This is the portion of the region's roadway system for which the most comprehensive data set is available. 

The TPB's regional freeway monitoring program is based upon comprehensive aerial photography of the region's freeways. Peak period congestion is monitored on a once-every-three-years cycle during the am and pm peak periods, and off-peak congestion is monitored once every five years during weekday mid-day and weekend mid-day. It provides a comprehensive data set of the region's freeway conditions and congestion.

The program and analysis provide the following information on the region's freeways:

  • A summary is developed of the overall conditions of the region's freeways. This data is then analyzed to indicate the most congested freeway locations, trends over time, and identification of factors associated with the congested conditions.


  • Example from 2006 CLRP. Click image to enlarge.
    A summary and description is developed of the top congested freeway locations in the region (see map to right). Planning, congestion management, or construction activity at or near these locations is also indicated to show what is being done to address this congestion.
  • Significant changes to congestion levels are noted at given locations or to the overall system, based on trend analysis over time, including where the impacts of previously implemented projects or congestion management strategies are notable.
  • A summary of technical information is developed regarding how the freeway condition information was developed, as well as associated performance measures.
  • Off-peak and weekend traffic conditions are monitored once every five years.

Arterial Monitoring Program 

Example from 2007 Arterial Monitoring Report. Click image to enlarge.

The TPB's regional Arterial Monitoring Program is based upon travel time information collected on a sample basis on a number of the region's non-freeway arterial highways.

The Program provides a data set of the region's arterial conditions and congestion. A sample of the arterials is taken, as there are thousands of miles of arterial highways in the region, and a comprehensive data collection effort would be cost-prohibitive. The data collection is limited to a number of important arterials, including the National Highway System (NHS).

From these data, a summary of the overall conditions of the region's monitored arterials is produced. These are categorized into a number of key types of urban situations. Examples from the data set are analyzed to illustrate the types of and reasons for arterial congestion in the region. As data are available, trends over time are shown.

Regional Transportation Data Clearinghouse 

TPB compiles roadway usage data as available, collected from the region's agencies and jurisdictions. These data may come from jurisdictions' regular traffic counting efforts, special studies, permanent count stations, or other sources.

The Clearinghouse program transforms these data into a format associated with the region's travel demand forecasting model. Compiled data are also associated with the estimated capacity of links on the region's roadway network, providing the opportunity to calculate estimated volume-to-capacity (V/C) ratios, a widely-used performance measure.

Special Studies and Data Collection Efforts  

The TPB and its member agencies undertake special studies or data collection efforts, on both one-time and recurring bases. Examples include monitoring of high-occupancy vehicle (HOV) systems, transit usage, and cordon counts of traffic on specified areas of the region.  

Defining and Analyzing Strategies 

This component involves identifying existing and potential strategies by the TPB Technical Committee, subcommittees, and staff. The TPB considers a number of demand management and operational management strategies.<<hyperlink>>

To define and analyze CMP strategies, the TPB's efforts consist of compiling and analyzing information for each of the following strategies:

  • Committees and staff identifying and advising the TPB on the analysis, methods, criteria, and performance measures used to analyze CMP strategies.
  • Compiling information on how and where a particular CMP strategy has been implemented.
  • Identifying a strategy as regional, corridor-wide, or local.
  • Performing qualitative or, if possible, quantitative analysis of the potential impacts of CMP strategies
  • Compiling information on potential impacts of strategies into summaries such as a “short list” and “long list.”

Implementing Strategies

This TPB effort is to focus on compiling information on strategies that have been implemented, particularly on a region-level basis. Also, the TPB is exploring how to assess previously implemented strategies. Feedback from the process is beneficial when it comes to updating the CMP and considering additional strategies and technical methods.

TPB currently reports on results of regional strategies implemented through the Commuter Connections Program.

Compiling Project-Specific Congestion Management Information

Pursuant to Federal regulations, the TPB encourages consideration and inclusion of congestion management strategies in all SOV capacity-increasing projects. This involves compiling and analyzing information in the Call for Projects documentation forms, which are submitted from regional agencies when the CLRP is developed.

The Call for Projects documentation requests any project-specific information available on congestion that necessitates or impacts the proposed project. Agencies compile this information from various sources, including TPB-published congestion information (if available), internal or other directly measured information, or by conducting engineering estimates of the Level of Service (LOS). TPB compiles and analyzes this submitted information, along with information from other CMP sources.

Specifically for SOV capacity-increasing projects, the TPB requests documentation that the implementing agency considered all appropriate systems and demand management alternatives to the SOV capacity. In the Call for Projects documentation a special set of SOV questions is completed by implementing agencies and the TPB compiles this information.