When we board a bus or train, how many of us ever think of what goes into operating fixed route public transit service? We see an operator behind the wheel, but behind them stand mechanics, service attendants, planners, schedulers, managers, and others whose efforts all help make the transit service we enjoy possible.

Similarly, how many of us ever think about everything that goes into the operation of the traffic control system? Behind the traffic lights and controls we see is an entire infrastructure. Often, while standing at Wilshire and Normandie, I would notice the camera on a tall pole watching the intersection. I knew it was a small link in the traffic system of Los Angeles but had only a vague
idea of how that system worked.

Then fortuitously, last year at the groundbreaking ceremony for the Gold Line Eastside Extension, I met Kartik Patel, who works for LADOT's traffic control section. I mentioned my interest in their operation and he offered to give our group a tour. We exchanged business cards. After some procrastination,
I followed up and arranged for a tour at 5 p.m. on Aug. 23.

On that date the following members assembled in the lobby of City Hall East in downtown Los Angeles: Henryka Maslowski, Perias Pillay (& guest), Hank Fung, Kent Landfield and Dana Gabbard. Because Kartik was on paternity leave, Mr. Gordon Kam of LADOT greeted us and escorted our small
group into the bowels of the building.

We took an elevator down to where the traffic control center is located, four floors beneath City Hall East. After making our way through corridors and past several doors (one of which was a formidable looking blast door), we arrived at the ATSAC control room.

We were introduced to Quan Tran of LADOT, who was to make the presentation. He stood before a bank of TV monitors as we settled into some chairs arrayed in front of him. Tran began by explaining that the Automated Traffic Surveillance and Control (ATSAC) System controls traffic flow by coordinating timing of traffic signals using information gathered from induction coils in the pavement, augmented with cameras to monitor key intersections. The system was introduced in the Coliseum area during the 1984 Olympic Games. It proved so successful that the city of Los Angeles decided to expand it citywide. To date, ATSAC has been
implemented at 3,100 of the 4,300 signalized intersections in Los Angeles, with another 157 being designed and 133 under construction this year. The gaps include
some areas of the San Fernando Valley and the I-5 corridor.

He then indicated the monitors behind him and noted they provide visual information on key intersections. As we named major locales about the city, he punched some buttons and - voila! - we were looking at the location itself. Soon we were watching live video of Rapid Buses at the intersection of
Wilshire and Westwood.

We asked if he could show us the contraflow bus lane on Spring Street in front of City Hall, but we couldn't locate an appropriate intersection to facilitate such a view. With the impending opening of the Orange Line, we were curious how it would interact with the traffic system. In moments we were looking at the intersection where the line crosses Reseda Blvd. And when questions arose regarding rail service, soon we were watching the Blue Line running along Washington Blvd. and Gold Line trains arriving at and departing from a station.

Besides the camera displays, there was also screens displaying information from the transponders on the Rapid Buses. These buses were represented by green and red icons, the latter color indicating vehicles that were behind schedule. Perias was disappointed to learn that only Rapid Buses that are running behind schedule, not all of them, get signal priority. He also inquired regarding the light rail trains and was told that all of them get priority all the time. The information gathered from the coils directs changes to the timing of street signals to improve traffic flow. New software currently being installed will be more flexible in
responding to conditions.

Los Angeles is on the cutting edge of traffic control. Tran explained only a few major metropolitan areas around the U.S. have begun to undertake similar systems for their traffic. Surprisingly New York has barely started launching theirs.

We were then shown another of the latest innovations - optical cable. These lightweight strands can carry thousands of signals linking the ATSAC system. By comparison we were shown a bulky heavy bundle of metal wires that the optical cable supplanted; as Henryka noted, the difference between the two was pretty striking.

Also we learned about plans to make realtime traffic information available to the public, which is already happening to some extent
via the site http://trafficinfo.lacity.org/

As the presentation concluded, we all expressed appreciation for the opportunity to see this modern marvel. Ours thanks to LADOT for their hospitality and forbearance of our many questions. [Thanks to Henryka Maslowski and Perias Pillay for suggestions and additional details to round-out this report]