Santa Clara staff say new Hitchbourne–Great America signal will ease congestion tied to Irvine housing project

City transportation staff told the Santa Clara City Council on Dec. 16 that a new traffic signal at Hitchbourne Drive and Great America Parkway — proposed as mitigation for the Irvine Company project at 2518 Mission College Boulevard — would provide an alternate access route into the Freedom Circle area and reduce projected congestion at nearby intersections.

Steve Chan, the city’s transportation manager, said the project’s transportation analysis determined a signal is needed to address the Irvine project’s impacts and that simulations show the signal would improve corridor operations from a Level of Service F to D during PM peak hours. “With the new signal in place, it would provide another pathway … and the level of service on both the Mission College Boulevard at Great America Parkway and Freedom Circle West will improve to a level of service D,” Chan said during the study session.

Why it matters: Council approved the Irvine Company project in March 2025 and included the signal as an entitlement condition. Staff said the signal is intended to keep project traffic off Mission College Boulevard — which the analysis forecasts will operate at LOS F without mitigation — by providing a southbound left turn from Great America Parkway into Hitchbourne Drive and improved egress routes to the 101 freeway.

What staff presented: Chan showed vehicle simulation runs for typical weekday AM and PM peak hours under two scenarios — with the Irvine project and the Greystar build‑out included, and with full Freedom Circle build‑out. Staff emphasized that the model represents average Monday–Friday peak hours and does not simulate atypical incidents or the full complexity of stadium event operations. Chan also noted the longest 95th‑percentile queue on Great America Parkway is projected at about 245 feet and that the distance from the 101 northbound off‑ramp to the proposed Hitchbourne signal is roughly 460 feet, which staff said avoids off‑ramp blockage.

Council concerns: Members repeatedly asked for additional details. Council member Jane asked for the Irvine project’s peak‑hour trip counts and how many signal cycles drivers would wait before clearing the intersection. Council members raised whether the model accounted for Sutter Health projects and improvements recently completed at Great America and Mission College. Several members urged the city to run additional “stress” simulations that push the system to identify where backups would form, and to show event‑day behavior because stadium egress, they said, is when traffic problems typically worsen.

On controls and events: Staff said the new Hitchbourne signal will be an actuated (on‑demand) signal with vehicle detection and that it can be adjusted or turned off during major stadium egress operations to prioritize event traffic. “All of the city’s traffic signal is what we call actuated. It only turns green … if there’s a vehicle there,” Chan said.

Costs and timing: The city manager told council the signal is part of the Irvine project’s entitlements and that Irvine will fund construction; staff estimated the signal cost at about $2,000,000. If council were to relieve Irvine of that obligation, the city would have to fund the improvement itself and potentially delay project timelines.

What’s next: Staff said they will continue to work with Irvine and can provide additional analysis if council requests it, including more detailed trip tables and expanded simulation scenarios. Council did not direct staff to stop the entitlement requirement; rather, they asked for more information before any final policy change.

Bottom line: Staff stand by the analysis that the Hitchbourne signal is a necessary mitigation tied to the approved Irvine entitlement; council members remain concerned about event‑period operation, cumulative projects such as hospital developments, and asked for more detailed data on trip generation and stress‑case simulations before taking any different action.