New details on a potential 101/92 connector project in San Mateo

“We’re currently in the environmental analysis phase, developing numerous technical studies to inform what the potential project benefits and impacts will be,” Senior Project Manager Carolyn Mamaradlo said during a recent Transportation Authority board meeting.

She added that the current phase has a target completion date of spring 2027.

“This is about a six-month delay … to allow for close coordination with Caltrans and additional technical work to ensure the project would not require a purchase of any homes or parks,” she said.

The prospect of acquiring such property garnered pushback to the project last year, as it originally involved acquiring more than 30 parcels of private property via eminent domain, which stipulates that owners may have to sell their land under certain circumstances, provided it will be used for public use.

Now, none of the options involve taking homes or parks, however, two of the options could involve taking portions of the existing utility easement — the area between property owner’s rear fences and the freeway sound wall — and portions of two residential yards along Norton Street, Mamaradlo said.

That’s part of the reason the completion of the current environmental and technical review phase has been delayed until 2027, as transit officials worked to develop another option that didn’t involve acquiring any new property.

According to current plans, the first alternative would add a direct connection from westbound State Route 92 to both directions of the Highway 101 express lanes, which could mitigate morning congestion; a reversible lane that could serve both morning and evening demands; or a connection from the Highway 101 express lanes to eastbound State Route 92 to alleviate evening traffic. The last option would not require any additional property acquisition.

While some transit advocates have pushed back on the project, claiming it could incentivize more vehicle travel, the agency has also been analyzing the impacts of cut-through traffic by those who try to avoid the often-congested 101/92 interchange by driving on side streets.

“In the mornings, about 1 to 2% of the freeway traffic are avoiding the interchange and using Third Avenue or Hillsdale instead,” Mamaradlo said. “While this sounds low, this represents a portion of the freeway traffic which could translate into hundreds of cars for those local streets. In the evenings, we see a much higher share, about 5 to 15% on those streets.”

Julia Mates, TA board member and mayor of Belmont, said she understands the concern many residents have about the project but noted that the volume of cut-through traffic also tends to have serious environmental and safety impacts.

“One reason we don’t want street traffic is that not only is it hard for residents but it’s not as good for the environment either, because you have stop signs and stoplights and you’re idling. You’re sitting there as opposed to continuing to move,” Mates said during the meeting. “That’s also problematic.”

The project is in the early stages, and full funding for the design and construction phases have yet to be secured. Construction could start as early as 2030 if financial gaps are filled and technical studies are quickly approved.