Technical Memorandum


DATE:   January 5, 2023

TO:         Boston Region Metropolitan Planning Organization

FROM:   Michelle Scott, Boston Region MPO Staff

RE:         Travel Time Reliability Performance Targets—2023 Update


The United States Department of Transportation requires states and metropolitan planning organizations (MPO) to establish two-year and four-year targets for travel time reliability performances measures pertaining to the National Highway System (NHS) for each four-year federal performance period. In October 2018, the Boston Region MPO voted to support statewide targets set by the Massachusetts Department of Transportation (MassDOT) to establish travel time reliability targets reflecting conditions as of the end of 2019 and of 2021.


In December 2022, MassDOT set targets for conditions as of the end of 2023 and 2025 for these travel time reliability measures, which are shown in Table 1. When setting these targets, MassDOT staff considered past travel time reliability measure values, as well as uncertain future travel demand following the COVID-19 pandemic and related public and private sector responses. Per federal requirements, the MPO must either agree to support these statewide targets or set targets specific to the Boston region. By adopting the Commonwealth’s travel time reliability targets, the MPO agrees to plan and program projects that help the Commonwealth achieve these targets. MPO staff recommends that the MPO vote to support MassDOT’s two-year and four-year targets for these measures and requests that the MPO take action to do so at its January 5, 2023, meeting.



Table 1
Travel Time Reliability Values and Massachusetts Performance Targets (2022–25)

Performance Measure

Desired Direction

Baseline Value (2021)

Boston Region Value (2021)

MA Two-Year
Target (2023)

MA Four-Year Target (2025)

Percent of person-miles on the Interstate Highway System that are reliablea






Percent of person-miles on the non-Interstate NHS that are reliablea






Truck Travel Time Reliability Index (for Interstates)b






States and MPOs determine these values by calculating a Level of Travel Time Reliability (LOTTR) metric for NHS roadway segments, which is the ratio of 80th percentile travel time to 50th percentile travel time, for four designated day and time periods. If a roadway segment has a LOTTR value of less than 1.5 for all four periods, that segment is considered reliable. States and MPOs then identify the person-miles of travel for each roadway segment using vehicle volumes and occupancy factors. They then divide the total person-miles on the roadway network that are reliable by the total person-miles on the roadway network.

b The Truck Travel Time Reliability (TTTR) Index is a ratio of 95th percentile truck travel time to 50th percentile truck travel time. States and MPOs calculate TTTR Index values for each interstate segment for five designated day and time periods and then multiply the largest ratio value of the five periods by the segment length. States or MPOs then sum these weighted segment lengths for all segments on the Interstate Highway System and divide that value by the length of the full Interstate Highway System.

CY = calendar year. LOTTR = Level of Travel Time Reliability. MA = Massachusetts. MPO = metropolitan planning organization. N/A = not applicable. NHS = National Highway System. RITIS = Regional Integrated Transportation Information System. TTTR = Truck Travel Time Reliability Index.  

Sources: National Performance Management Research Data Set, RITIS, Massachusetts Department of Transportation,  and the Boston Region MPO staff.





The Boston Region Metropolitan Planning Organization (MPO) operates its programs, services, and activities in compliance with federal nondiscrimination laws including Title VI of the Civil Rights Act of 1964 (Title VI), the Civil Rights Restoration Act of 1987, and related statutes and regulations. Title VI prohibits discrimination in federally assisted programs and requires that no person in the United States of America shall, on the grounds of race, color, or national origin (including limited English proficiency), be excluded from participation in, denied the benefits of, or be otherwise subjected to discrimination under any program or activity that receives federal assistance. Related federal nondiscrimination laws administered by the Federal Highway Administration, Federal Transit Administration, or both, prohibit discrimination on the basis of age, sex, and disability. The Boston Region MPO considers these protected populations in its Title VI Programs, consistent with federal interpretation and administration. In addition, the Boston Region MPO provides meaningful access to its programs, services, and activities to individuals with limited English proficiency, in compliance with U.S. Department of Transportation policy and guidance on federal Executive Order 13166.

The Boston Region MPO also complies with the Massachusetts Public Accommodation Law, M.G.L. c 272 sections 92a, 98, 98a, which prohibits making any distinction, discrimination, or restriction in admission to, or treatment in a place of public accommodation based on race, color, religious creed, national origin, sex, sexual orientation, disability, or ancestry. Likewise, the Boston Region MPO complies with the Governor's Executive Order 526, section 4, which requires that all programs, activities, and services provided, performed, licensed, chartered, funded, regulated, or contracted for by the state shall be conducted without unlawful discrimination based on race, color, age, gender, ethnicity, sexual orientation, gender identity or expression, religion, creed, ancestry, national origin, disability, veteran's status (including Vietnam-era veterans), or background.

A complaint form and additional information can be obtained by contacting the MPO or at

To request this information in a different language or in an accessible format, please contact

Title VI Specialist
Boston Region MPO
10 Park Plaza, Suite 2150
Boston, MA 02116

By Telephone:
857.702.3700 (voice)

For people with hearing or speaking difficulties, connect through the state MassRelay service:

  • Relay Using TTY or Hearing Carry-over: 800.439.2370
  • Relay Using Voice Carry-over: 866.887.6619
  • Relay Using Text to Speech: 866.645.9870

For more information, including numbers for Spanish speakers, visit