Private eyes are watching you Private eyes are watching you (June 01, 2005)

New computer system allows traffic officials to watch your every move in an effort to streamline commute

by Bill D'Agostino

In a room no bigger than many walk-through closets, there is a computer that knows when you're waiting at a traffic signal.

It knows when you push the button for your turn to cross Embarcadero Road. It knows when your car is idling at an intersection on Alma Street. It knows when your bike has tripped the electric loop under the pavement along Middlefield Road.

And, with a few clicks of a mouse, the City of Palo Alto's transportation engineers can watch those intersections, observe you waiting and make a real-time adjustment to the length of your red light -- if need be.

The new computer system is the first in what city officials hope will be a series of upgrades to the city's traffic signals in coming years.

"This opens up a lot of doors," transportation engineer David Stillman said last week. As he spoke, he demonstrated the new system.

An animated image of Embarcadero and Middlefield roads flashed on both a small computer monitor and on a large plasma screen overhead. Simple figures represented the cars and pedestrians; green arrows on the road showed which signals had green lights. The new upgrades allow the city to squeeze efficiencies out of the streets without widening them, Stillman added.

"Palo Alto has a policy of not widening roads or intersections, so we just need to make better use of what we have," Councilwoman Yoriko Kishimoto said.

Traffic experts agree that upgrading traffic signals can be one of the most cost-effective ways to reduce delays, fuel consumption and travel times. Last month, the National Transportation Operations Coalition gave the country a "D-" for cities, counties and states' overall administration of traffic signals.

Projects such as Palo Alto's were cited as badly needed. Nearly all of the 97 intersections the city controls have recently been upgraded to communicate with the computer. (A few located near the Stanford Shopping Center will be improved in coming months.)

Two-thirds of the $1.5 million for the new upgrade came from federal, state and regional grants.

The next step, after the physical upgrade is completed, is to let the computer start making adjustments to the lengths of some stop lights, based on the traffic conditions it observes.

The computer, located in a building at the Municipal Services Center near the Baylands, does not use cameras to watch the intersections, although that could be another upgrade in the future. Rather, using fiber-optic cables, the computer is connected to vehicle-triggered wire loops under the pavement and the pedestrian-triggered buttons on the sidewalk.

Traffic engineers create a plan to change the timing of traffic signals to known conditions during different times of the day. The wire loops and buttons let the computer know when a pedestrian or vehicle is waiting and in need of a chance to proceed.

Prior to the project, the city's traffic signals had not been substantially improved since they were installed in the 1970s. With the old system, upgrading the plan was an arduous task, requiring engineers to visit the intersection and open up the green "control boxes" by the side of the road. Now the plan can be upgraded immediately, using the computer in the Baylands or City Hall.

Also under the old system, city engineers often did not immediately know when traffic signals stopped communicating with the entire system and stopped running according to the plan.

One consistent goal of that plan is to allow drivers riding along a stretch of a road with numerous traffic signals to get green light after green light, what Stillman called "synching" the lights.

There is still a major hindrance to "syncing" the entire system of Palo Alto's traffic signals: many of the city's major intersections -- along Page Mill Road, El Camino Real and Foothill Expressway -- are not controlled by the city, but by Santa Clara County or Caltrans.

So while most of the signals along Middlefield Road are run by the city, the county runs the one at Middlefield and Page Mill roads. The city attempts to synchronize the lights on Middlefield Road in the north and south sections of the city, but cannot sync the two parts together, Stillman noted.

That kind of coordination was one of the other major factors cited by the national survey as needing improvement nationwide.

Staff Writer Bill D'Agostino can be e-mailed at bdagostino@paweekly.com.

E-mail a friend a link to this story.