Lafayette commission backs concept to restrict right turns on red along Mount Diablo Boulevard

The City of Lafayette Transportation and Circulation Commission voted to forward a conceptual plan to City Council to restrict right turns on red at three signalized intersections along Mount Diablo Boulevard — Oak Hill Road, Moraga Road and First Street — with the aim of reducing conflicts between motorists and people walking or bicycling.

Commission chair Barton Khan opened the meeting and introduced the item as a response to recurring safety concerns along Mount Diablo Boulevard. Patrick (city transportation staff) and consultants Bruno Lierz and Sarah Chan of Pearson presented a traffic-operations and safety analysis that recommended implementing the restrictions at all times rather than only when pedestrians activate a signal.

The consultant presentation summarized field observations, vehicle/pedestrian/bicycle counts concentrated on weekday peak periods and a focused school PM peak (about 2:45–3:45 p.m.). Bruno Lierz reported that the study found total conflict points between vehicles and pedestrians/bicyclists would decline by roughly half at the studied intersections if right-on-red turns were prohibited at all cycles — for example, conflicts fell from 15 to 7 at the Moraga Road and First Street intersections in the consultant model. Lierz said vehicle-pedestrian conflicts decreased from 23 to 12 and vehicle-bicycle conflicts from 19 to 8 in the modeled scenarios presented to the commission.

Patrick said the study aligns with Lafayette’s Local Roadway Safety Plan and noted a recent collision at First Street involving a vehicle turning right on red and a child crossing, a collision that partly motivated the study. “This project is a pretty good opportunity to address the collision that happened a couple weeks ago,” Patrick said.

On traffic operations, consultants reported that average delay increases were minimal (generally under 10 seconds) for most intersections and the AM commute peak, but that Moraga Road at Mount Diablo showed an increase greater than 10 seconds in the school PM peak. The presenters said that even at that intersection the modeled queues remained contained and did not spill back to adjacent intersections in the modeling runs. The study team recommended signal-timing optimization and consideration of right-turn overlap phases or LED “NO TURN ON RED” blank-out signs to reduce delay impacts while maintaining safety gains. They also identified the countywide CCTA Smart Signals project as an opportunity to coordinate further timing improvements.

Commissioners pressed staff and consultants on several operational concerns, including potential queueing during school pickup, enforcement of any new restriction, whether signs would be pedestrian-activated or always on, and whether the city could implement leading pedestrian intervals (LPIs) at particular crosswalks as a complementary measure. Commissioner Greg Brown asked whether the intersections in the study already had leading pedestrian intervals; staff replied they do not at the three study intersections but that nearby intersections west of Lafayette Circle East include pedestrian-first timing.

Commissioner Michelle Sahar emphasized enforcement as essential: “There’s no point in installing the signs if they’re not enforced,” she said, noting existing locations where static no-turn signs are commonly ignored. Staff responded that the city would coordinate with Lafayette Police Department for enforcement if the restriction is pursued.

After discussion the commission voted to forward the concept to the City Council for conceptual approval (motion text: “Forward Mount Diablo Boulevard right-turn-on-red restrictions project to City Council for conceptual approval”). The formal tally recorded by staff was four in favor and one abstention. Patrick said that if Council approves conceptually, the city would move into design and return to the commission with implementation details, at which time staff and commissioners would refine decisions such as whether restrictions are active every cycle or only when pedestrians call the crosswalk and how signal timing and enforcement would be phased with the CCTA Smart Signals work.

The commission’s action is a referral to City Council to pursue project design; it does not yet adopt final signal phasing, signage, or enforcement protocols. Staff emphasized next steps would include signal-timing optimization, potential blank-out signs or right-turn overlaps, and further coordination with the county Smart Signals project and Lafayette Police for enforcement planning.