About Us

COG is the one place in metropolitan Washington that regularly brings leaders together to develop solutions to the region's major challenges. COG prepares plans enabling the region to receive federal funding, provides members with research and data to inform decision-making, and offers a wide range of programs, including commuter services, cooperative purchasing, technical assistance and grants, and public outreach campaigns.

Transportation

Through the National Capital Region Transportation Planning Board (TPB), area officials, planners, and engineers ensure a well-managed and maintained transportation system. The TPB, which is staffed by COG, conducts the federally mandated transportation planning process for the region and ensures the uninterrupted flow of federal transportation funds that area jurisdictions receive.

Environment

COG's work engages leaders in various environmental fields from water quality experts to climate scientists. Together, they are advancing regional efforts to restore local waterways, improve air quality, reduce greenhouse gas emissions and address climate change, promote recycling, and enhance and preserve green space and agriculture.

Community

Area officials and experts, including planning and housing directors and child welfare and health officials, work together with their counterparts at COG to help shape stronger communities throughout the region.

Homeland Security & Public Safety

COG brings police chiefs, fire chiefs, emergency managers, and other leaders together as part of its work to strengthen regional public safety coordination, homeland security planning, and emergency communication.

Transportation

Congestion Dashboard

Regional Trends

Travel Time Index (TTI), defined as the ratio of actual travel time to free-flow travel time, measures the intensity of congestion. The higher the index, the more congested traffic conditions it represents, e.g., TTI = 1.00 means free flow conditions, while TTI = 1.30 indicates the actual travel time is 30% longer than the free-flow travel time.

Planning Time Index (PTI), defined as the ratio of 95th percentile travel time to free flow travel time, measures travel time reliability. The higher the index, the less reliable traffic conditions it represents, e.g., PTI = 1.30 means a traveler has to budget 30% longer than the uncongested travel time to arrive on time 95% of the times (i.e., 19 out of 20 trips), while TTI = 1.60 indicates that one has to budget 60% longer than the uncongested travel time to arrive on time most of the times.

Background

Inspired by various agency and jurisdictional dashboard efforts around the country (e.g., the Virginia Department of Transportation Dashboard), driven by the MAP-21 legislation and the emerging probe-based traffic speed data from the I-95 Corridor Coalition Vehicle Probe Project, this quarterly updated National Capital Region Congestion Report takes advantage of the availability of rich data and analytical tools to produce customized, easy-to-communicate, and quarterly updated traffic congestion and travel time reliability performance measures for the Transportation Planning Board (TPB) Planning Area. The goal of this effort is to summarize the region's congestion and the programs of the TPB and its member jurisdictions that would have an impact on congestion, to examine reliability and non-recurring congestion for recent incidents/occurrences, in association with relevant congestion management strategies, and to prepare for the MAP-21 performance reporting. For more information and technical details, please see the full report.

Quarterly Congestion Reports