Riverside County’s transportation commission has landed a $25 million federal grant to help pay for a $178 million overhaul of one of Southern California’s most congested freeway stretches, where more than 300,000 vehicles squeeze through the Riverside-Orange county line every day. The money will go toward the SR-91 Eastbound Corridor Operations Project, known as 91 ECOP, which adds a three-mile nontolled auxiliary lane between the SR-241 connector and SR-71 near Green River Road.
The U.S. Department of Transportation awarded the funding through its BUILD grant program, a nationally competitive discretionary program that targets transportation infrastructure with significant local or regional impact, according to the Record Gazette. Riverside County Transportation Commission Chair Raymond Gregory said continued investment in the SR-91 corridor is needed to keep communities moving, and he thanked the U.S. Department of Transportation for backing the project through the grant program. Gregory also credited Representatives Ken Calvert and Young Kim for supporting the project’s grant application, saying the award recognizes the importance of the work.
What the Widening Actually Fixes
Beyond the new auxiliary lane, the project includes constructing retaining walls, widening two bridges, replacing overhead signs, and adding rockfall mitigation measures along the corridor. RCTC is advancing the work in partnership with Caltrans and the Orange County Transportation Authority, and officials say the improvements are meant to improve traffic flow, enhance travel reliability across the region, and support economic development. Construction on the 91 ECOP is expected to begin in 2028 and will be funded through a mix of federal, state, and local dollars along with toll revenues.
RCTC has already been laying administrative groundwork this month. In August, the commission considered a cooperative agreement worth up to $5.656 million with Caltrans covering construction work on the eastbound project, per Civic IQ. RCTC adopted a progressive design-build delivery model for the project in late 2025, a strategy that folds design, environmental monitoring, permitting, and construction into a single contractor process, according to filings reviewed by HigherGov.
Part of a Two-Decade Master Plan
The 91 ECOP is not a standalone fix. It’s part of broader work along the State Route 91 corridor. The eastbound work builds directly on recent progress nearby: RCTC opened a two-mile nontolled general lane on westbound SR-91 between Green River Road and SR-241 in Anaheim Hills back in January 2022, and by June 2025 the commission was nearing completion of a separate $137 million project replacing a single-lane loop connector between eastbound SR-91 and northbound SR-71 with a new two-lane direct connector ramp in Corona, according to footage posted by RCTC on Facebook…