The number of bicyclists and pedestrians has also gone up, while the number of speeders traveling faster than 37 mph has decreased because of changes aimed at calming traffic along the south Palo Alto route, the study found.
The new data was unveiled Tuesday night, June 12, at a community meeting at Juana Briones Elementary School. Chief Transportation Official Jaime Rodriguez summarized the results of the trial project, which included shrinking the number of lanes from four to three in segments along the corridor and some changes to the timing of traffic signals. The study area runs from Gunn High School to El Camino Real.
The project is the second of two phases that encompass the Charleston-Arastradero Road corridor. The road was noted for excessive speeding and high volumes of traffic in an area that serves 11 schools, multiple preschools, three community centers, six parks and Stanford Research Park.
In 2008 the Palo Alto City Council decided to make the alterations to Charleston Road — phase 1 — permanent.
Perhaps the most significant result of the Arastradero trial has been a fivefold decrease in vehicle accidents involving bicyclists or pedestrians, Rodriguez said. Since the project began in September 2010, the crashes went from six in 2009 to one for each year thereafter. The data runs through April 2012.
The good news comes despite more bicyclists using the route. Now, roughly as many bikes as cars travel the corridor during the peak school commute in the morning, Rodriguez said. In 2003, there were 807 students cycling to Gunn High and Terman Middle School; there were 1,342 in 2011.
But some residents who attended Tuesday's meeting took issue with the comparison of bike and car traffic, pointing out that the car counts were taken for Arastradero only, while the bike traffic included nearby residential streets along the school route. Other residents said it was still a fair comparison of cars and bikes because most of those cyclists end up on Arastradero at some point on their way to school.
Traffic collisions overall, not including at El Camino Real, decreased at three main points where they have been high: at Georgia Avenue and at Terman and Coulombe drives. There was not a significant drop in accidents involving cars only.
The speed of traffic, another concern along the 25 mph corridor, has slowed by 2 to 5 mph among 85 percent of drivers (known in traffic law as the 85th percentile — the benchmark speed for any road), the study noted.
High-speed driving also dropped significantly after the trial began. Vehicles traveling more than 37 mph westbound during off-peak hours dropped from 12.8 percent to 3.8 percent west of Georgia and from 15.3 percent to 2.4 percent east of McKellar Lane, the study showed.
One of residents' greatest concerns, that the road changes would cause increased cut-through traffic through neighborhoods, seems in large part not to have occurred, Rodriguez said.
During the morning commute, cut-through traffic numbers remained relatively steady — with the exception of along Maybell Avenue.
Residents were split on how they felt about the results. Some said they have trouble exiting neighborhood streets to get onto Arastradero because of long queues at Foothill Expressway in the afternoons.
But other residents dismissed the complaints as mere quibbling.
"Do you really want to return to the Indianapolis 500?" a resident asked.
"The controls you have put on will be needed more than ever," he said, noting the planned development of homes and hotels such as at the former Palo Alto Bowl site on El Camino and companies' expansions at the Stanford Research Park.
Arastradero resident Peggy Kraft agreed.
"I think the statistics are astonishing. I believe this keeps our kids safer. You're not going to have a miracle where 15 percent of the people are going to leave the city and stop driving here," she said.
The Arastradero project trial began in 2010 and was extended to this summer after the high school changed its school-bell timing to help ease rush-hour traffic congestion.
The study will be presented to the Planning and Transportation Commission for review in July.