Congestion Relief Alternative for SR99

SR 99 and SR 120 are critical regional corridors serving commuters, goods movement, and local traffic. Over the past several years, increasing traffic volumes have resulted in recurring congestion during peak travel periods. When congestion occurs on SR 99 and SR 120, many drivers rely on navigation applications or local knowledge to seek alternate routes. As a result, traffic diverts from the state highway system onto local streets within Ripon. These local roadways were not designed to accommodate high volumes of regional cut-through traffic. The resulting impacts to the City of Ripon include: Longer emergency response times Reduced safety for pedestrians, bicyclists and local drivers Increased law enforcement demands for traffic control and vehicle code enforcement Accelerated roadway wear and maintenance needs Increased noise and air pollution in residential neighborhoods Caltrans does not currently have plans to address this congestion through capacity-increasing improvements on the mainline system. As a result, the issue is being addressed by regional and local partners, with SJCOG taking a lead role while coordinating with Caltrans. SJCOG is leading the 99/120 Interchange Project, which is being delivered in phases. The first phase termed Phase 1A is currently under construction and is anticipated to be completed in summer 2026. Phase 1A includes: Replacement of the Austin Road overcrossing Widening SR120 connector ramp to southbound SR99 Improvements to local streets Despite these improvements, congestion on the state highway system - and the resulting cut-through traffic through Ripon - is expected to persist. In 2020, Mark Thomas prepared the Regional Cut-Through Mitigation Memo, which identified 12 potential measures ranging from signal timing modifications to auxiliary lanes and bridge widening. While some measures can be implemented locally with minimal impact, larger-scale solutions require regional coordination with Caltrans. Even then, long-term benefits are constrained by right-of-way limitations along SR 99. The City of Ripon's General Plan identifies the Olive Avenue Expressway interchange with SR 99, a future expressway, and an ultimate Stanislaus River crossing into an adjacent county as the long-term solution to relieve regional cut-through traffic. This planned facility is intended to function as a regional bypass and reduce congestion on local streets. As stated previously, the study will commence following completion of the SR 99/120 Phase 1A construction. The exact time (to start the study) will be submitted by the consultant (within the proposal) based upon their recommendation on the best time to gather the traffic data.