Mike Tassano, city traffic engineer, told the City Council on Tuesday that state law requires speed surveys at least once a year to make sure posted speeds conform to the speeds that 85% of motorists are driving. Certain expectations are allowed based on driveways, pedestrian traffic and other considerations, he said. Otherwise, speeds and posted speed limits must conform.
Police Chief David Spiller said that speed limits that are not in conformance with the 85% rule cannot be enforced by police.
First Street, between Ray Street/Vineyard Avenue and where First turns into Stanley Boulevard, is posted at 35 mph but motorists are driving it at 40. The survey found the same on Gibraltar Drive between Hopyard and Stoneridge. As a result, speed limits on both sections of those streets will be increased to 40 mph. Johnson Drive between Stoneridge and Commerce Circle also will now be posted at 40 mph.
The basis for the 85 percentile comes from the California Vehicle Code's "Basic Speed Law." Traffic engineers use the 85 percentile speed as a benchmark for what the majority of drivers feel is a safe speed. Speed limits set too low when most drivers are traveling faster can pose safety hazards, Tassano said.
Pleasanton streets now posted at 30 mph that will be raised to 35 mph are Bernal Avenue between Vineyard and Nevada; Chabot Drive between Owens and Inglewood; Dublin Canyon Road between Laurel Creek Drive and Foothill; Inglewood Drive between Hopyard and Willow; and Laguna Creek Lane between Valley and West Lagoon Road.
Pleasanton streets now posted at 25 mph that will now be raised to 30 mph are Deodar Way between Foothill and Stoneridge Mall Road; and Valley Avenue between Case Avenue and Sunol Boulevard.
Speed limits on Willow Road now posted at 40 mph will be reduced to 35 mph, and Owens Drive between Chabot Canal and Rosewood will be cut from 45 to 40 mph.
Streets where speed limits are being reduced by 5 mph include portions of Johnson Drive, Pleasanton Avenue and Springdale Avenue.
The City Council approved the speed limit changes 3-1 with Councilman Jerry Pentin opposed, saying the higher speeds on some streets could endanger bicyclists.