Integrating Operations into Planning and Programming

Communicating TSMO

Analysis and Performance Measurement

Regional Collaboration and Coordination

Organizing for Operations

Mainstreaming TSMO

Transportation Systems Management and Operations (TSMO) Plans

Congestion Management Process (CMP)

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Transportation Demand Management

Traffic Incident Management



Travel Time Reliability

Travel time reliability reflects the variability of travel time. A reliable transportation system dependably provides users with a consistent range of predictable travel times. Travel time reliability is one of the core performance outcomes of many Transportation Systems Management and Operations (TSMO) strategies. TSMO strategies can help meet multiple operations objectives in the reliability area reducing variability and improving buffer and planning times. More than half of the congestion experienced by travelers is estimated to be caused by non-recurring events, such as inclement weather, work zones, special events, and traffic incidents. TSMO strategies address these conditions by systematically identifying and addressing the root causes of delay and variability, thereby making travel times more reliable. By doing this, extra-long delays associated with the non-recurring events are reduced and overall system performance is improved.

Below are some FHWA resources that highlight the basics of travel time reliability and its applicability with TSMO strategies and programs.

  • FHWA Travel Time Reliability Measures Website - provides a basic understanding of what travel time reliability is and why it is important.
  • FHWA TSMO-related programs - links that highlight various performance measurement activities that include travel time reliability.
  • Does Travel Time Reliability Matter? (Primer, Fact Sheet, Flyer, Video) - explores the importance of travel time reliability, the consequences of an unreliable transportation system, and how TSMO can improve travel time reliability.
  • TSMO: Getting More from Our Existing System Infographic (PDF 190kb, [8.5”x11”], PDF 194KB [11”x17”], PPTX 3.7MB, PPTX [References at End]) - highlights travel time reliability as one of the benefits of TSMO.
  • Urban Congestion Trends - provide annual snapshots of congestion in the United States by summarizing recent trends in congestion using key metrics in travel time reliability, such as travel time index and planning time index.
  • Methods to Improve Freight Performance, Reliability, and Bottlenecks Workshop (Report, Presentation) - explores strategies to improve Truck Travel Time Reliability (TTTR) and mobility at truck freight bottlenecks..


Travel time reliability was a major area of research for the second Strategic Highway Research Program (SHRP2), which focused on developing basic analytical techniques, design procedures, and institutional approaches to understand and address the unpredictable congestion that makes travel times unreliable. Products from SHRP2 can be found on the FHWA SHRP2 Reliability website. Below are some of the products that highlight the connection between TSMO and travel time reliability.

SHRP2 also produced products to incorporate travel time reliability into operations and planning data and analysis tools to support TSMO efforts. A set of 18 case studies and four pilot site reports (CaliforniaFloridaMinnesotaWashington) highlight findings from transportation agencies that implemented reliability data and analysis tools developed under SHRP2.

MAP21 Travel Time Reliability Performance Metrics and Performance-Based Planning

The Moving Ahead for Progress in the 21st Century Act (MAP-21) and the Fixing America’s Surface Transportation (FAST) Act established new performance-based planning requirements for State Departments of Transportation (DOT), Metropolitan Planning Organizations (MPO)MPOs), and providers of public transportation services. These requirements include tracking and reporting key reliability metrics.

  • Percent of the Person-Miles Traveled (PMT)person-miles traveled on the Interstate that are Reliable
  • Percent of PMT on the non-Interstate National Highway System (NHS) that are Reliable
  • TTTR Index Measure

The latest metrics are broken down by state on the FHWA State Performance Dashboard and Reports website. In addition, State DOT/MPO Performance Reports, Dashboards and Plans are also compiled. Given that Performance Measurement is an essential dimension to advancing TSMO programs and capabilities, tracking these key reliability metrics can provide much value for state and local transportation agencies.