Traffic Study Shows Smaller Than Expected Lab Impact

January 15, 1999

By Ron Kolb,

A recent joint Berkeley Lab and City of Berkeley traffic study on one of the city's busiest corridors has found that drivers going to and from the Laboratory represent a significantly smaller proportion of the traffic flow than had previously been assumed.

According to the "origin-destination" study, conducted on Sept. 22, Laboratory-related trips accounted for less than seven percent of all traffic passing along the Warring Street corridor at the southeast corner of the Berkeley campus. Some city officials and neighborhoods had been assuming that as much as 30 percent of the traffic was attributable to Laboratory business.

"This is good news," said Rich McClure, facilities planner at the Laboratory. "It reflects the Laboratory's commitment to and success in developing transportation alternatives which support our environmental stewardship, as well as our positive relations with our neighbors."

Added McClure, "The BART-bus shuttle combination, plus increased car pooling incentives, improved bicycle accommodations, expanded pedestrian access, and the installation of a card-key scanner at the Grizzly Gate are contributors to a reduced Laboratory impact on the Warring corridor."

The Belrose/Derby/Warring corridor is busy most of the day, as it provides direct access between central and northern Berkeley and points south, including the Claremont/Ashby junction and the access roads to Highways 13 and 24.

An estimated 20,000 cars pass through the corridor on any given day. Even though that represents about 5,000 fewer cars than the average counted 11 years ago, the busiest times of the day still tend to clog traffic due to winding streets and stop signs.

During a 12-hour period on one typical Wednesday in September, driversósix at a timeówere asked to divert briefly into queues, set up both northbound and southbound, and answer 45-second questionnaires about their trips. A total of 1,342 surveys were conducted in the northbound direction, and 1,415 in the southbound direction.

At the end of the day, Berkeley Lab accounted for 6.8 percent of the northbound traffic and 4.1 percent of the southbound traffic. During the peak morning commute (8 to 9 a.m.), the Laboratory was the destination of 12 percent of all northbound drivers; for the peak evening commute (4:45 to 5:45 p.m.), it was the origin of 6.9 percent of the southbound drivers.

By contrast, the Berkeley campus was the destination point for 37 percent of the northbound drivers and the origin point of 27 percent of the southbound drivers. During peak commute times, proportions of the traffic going to or coming from Cal accounted for 79 percent in the morning and 54 percent in the evening.

Drivers going to and from North Berkeley and downtown Berkeley accounted for the largest percentage of non-University traffic traversing the corridor during the day.

Other general findings reported in the survey include:

  • Southbound traffic is significantly heavier than northbound traffic.
  • About 61 percent of southbound drivers take Tunnel Road eastbound after traveling through the corridor.
  • Overall traffic volumes have declined over the past decade on this corridor.
  • 56 percent of peak-hour southbound drivers have a local destination in Berkeley, Oakland or Alameda.
  • Single-occupant vehicles predominate.
  • Almost 75 percent of the drivers indicated they used this corridor at least two or three times a week.

McClure said the survey information will be used by the city in its transportation planning activities. The effort was conducted by Fehr and Peers Associates of Lafayette.

It was the first of its kind at that location in 20 years and had the support of the City of Berkeley Planning and Police departments. The city Transportation Commission was also consulted.