The U.S. Interstate Highway System will need to be rebuilt and expanded to meet the nation’s growing transportation needs, according to a report released by TRIP, a national transportation research nonprofit.
The report, Restoring the Interstate Highway System: Meeting America’s Transportation Needs with a Reliable, Safe & Well-Maintained National Highway Network, looks at the Interstate system’s use, condition, and benefits, and the findings of a 2019 report prepared by the Transportation Research Board (TRB) at the request of Congress as part of the FAST Act on the condition and use of the Interstate system and on actions required to restore and upgrade the system.
According to the TRB report, the Interstate system has a persistent and growing backlog of physical and operational deficiencies as a result of age, heavy use, and deferred reinvestment, and is in need of major reconstruction and modernization. The TRB report concludes that annual investment in the Interstate Highway System should be increased approximately two-and-a-half times, from $23 billion in 2018 to $57 billion annually over the next 20 years.
The TRIP report found that since 2000, travel on the Interstate system has increased at a rate nearly triple that at which new lane capacity is being added. As a result, 47% of urban Interstate highways are considered congested during peak hours. Travel by combination trucks on the Interstate increased 45% from 2000 to 2018, nearly double the 25% rate of travel growth for all vehicle travel during the same period.
The design of the Interstate—which includes a separation from other roads and rail lines, a minimum of four lanes, paved shoulders and median barriers—makes it more than twice as safe to travel on as all other roadways. The fatality rate per 100 million vehicle miles of travel on the Interstate in 2018 was 0.58, compared to 1.32 on non-Interstate routes. TRIP estimates that additional safety features on the Interstate Highway System saved 5,930 lives in 2018.
TRIP’s report finds that while pavement smoothness on most segments of the Interstate system is acceptable, the crumbling foundations of most highway segments need to be reconstructed, and that continued resurfacing rather than addressing underlying foundational issues provides diminishing returns and results in shorter periods of pavement smoothness. As the aging system’s foundations continue to deteriorate, most Interstate highways, bridges, and interchanges will need to be rebuilt or replaced. According to the TRIP report, pavements on 11% of Interstate highways are in poor or mediocre condition. More than one quarter (27%) of Interstate bridges are in need of repair or replacement.
Based on the findings of the TRB Interstate report, TRIP has provided a set of recommendations for the restoration of the Interstate Highway System, which includes: the foundational reconstruction of Interstate highways, bridges, and interchanges; improvement to roadway safety features; system right-sizing, including upgrading of some roadway corridors to Interstate standards; adding needed additional highway capacity on existing routes; adding additional corridors; and modifying some urban segments to maintain connectivity while remediating economic and social disruption.