Since October, Alameda traffic from 7:30 to 9 a.m. and 4:30 to 6 p.m. has been treated to longer green lights between Santa Cruz and Valparaiso avenues. The county acted in response to residents' complaints of cut-through traffic on parallel arterials such as Altschul and Cloud avenues.
Meanwhile, drivers entering the Alameda from side streets may find themselves queuing more often.
With the new timing, a passage uninterrupted by crossing pedestrians or slow traffic would allow a platoon of vehicles traveling at the speed limit to see four green lights, said Lisa Ekers, the road operations manager for the San Mateo County Public Works Division.
"Things have to resettle as the drivers relearn their timing and speed," Ms. Ekers said. "People will eventually learn the pace that gets them through all the greens."
The impact, so far, on cut-through traffic? "None whatsoever," said Mike Maletic, a Cloud Avenue resident who represents the Val Avy Group, a loose collection of about 40 households between Valparaiso and Avy avenues who complained to the county.
"We're never been really sold on the idea that improving the flow on Alameda would solve our problem," he added.
Asked to comment, Ms. Ekers replied that people's views may differ and that she has heard the opposite, that traffic is down on Altschul and Cloud.
Give it six months, she added. Public works will evaluate traffic volume and speeds then and make adjustments as necessary.
Discontent with the new timing is evident at La Entrada middle school on Sharon Road a fifth of a mile west of the Alameda.
PTA member Kristin Smith, in a recent letter to Supervisor Rich Gordon (reprinted in the Dec. 5 Almanac), described vehicle queues backed up to the school while waiting for the light to change; pedestrians, including children, crossing against red lights; and impatient drivers giving up and driving through extended red lights when the Alameda is empty.
"My biggest concern is for the students trying to get to school," she said. "My son has seen students crossing the Alameda on red lights, and I have seen many pedestrians cross on red lights since the timing was changed."
Assistant Principal Pattie Dullea said the school continually advises students to cross the street safely. The morning vehicle queues on Sharon Road are complicating student drop-offs, including for the buses, she said.
In her letter, Ms. Smith asks Mr. Gordon to change the timing back to what it was before.
Mr. Gordon, in an interview, described the matter as a cost-benefit analysis seeking the greatest good for the greatest number of people. "We will try to fully understand what is the impact on Sharon (Road) and if there is any way to tweak that to make it better," he said.
Cloud Avenue, by Mr. Maletic's back-of-the-envelope calculations, should have 200 trips a day but endures 1,400 according to a county estimate, he said.
Inappropriate speed and belligerence from cut-through drivers is a common problem, he said. He sometimes cruises his street at 18 to 20 mph to set an example, but drivers try to pass him. "I feel we have the right to have neighborhood traffic, not 35 to 40 mph traffic," he said. "We really want a safe place for our kids to be in the street without being hit."
The 3-foot-high plastic yellow and green men sticking their warning flags into traffic have been tried, but they are stolen or run down, he said, adding: "I'd need to have about 15,000 of those."
Some commuters even avoid traffic counters. He said he has seen people drive up onto his lawn or even turn around to avoid tripping one.
Ideally, the residents would like their roads closed to commuters or maybe made into one-way streets, but "we're not really sure which way," he said.