AC Transit Uses Satellites and Computers to Improve Scheduling
By Sarah Neal
AC Transit is spending $16 million to make its schedules more effective. But the solution is late - three years late.
Jim Cater, dispatch director for AC Transit, says functional equipment has been installed to track all 800 buses by satellite. But others at AC say the new system is plagued by technical problems, with buses traveling in and out of range - like a bad cell phone connection.
"You're getting into 'does this stuff work, or not?' - Underline the not," said John Twichell, a planning manager for AC Transit.
The system, called SATCOM 2000, was purchased in 1998 to track bus locations and automatically tabulate on-time performance.
But neither of these features is fully functional yet, and the project is three years behind schedule. While SATCOM can theoretically locate every bus, AC cannot use this information as planned without software to identify route and schedule problems.
"There's information you can use, and information you can't use, I think this is the second kind," says AC Transit board member Alice Creason of the information SATCOM 2000 is currently providing.
When the system does work, AC will discard traditional timetables and replace
them with a so-called headway system, which keeps buses at specified intervals.
Adhering to a schedule "is nearly impossible to do," AC Transit operations
technical administrator John Rudniski says. Any driver can be delayed by "uncontrollable
variables:" traffic, weather, unruly passengers or people in wheelchairs.
The headway system, focused on maintaining a specified amount of time between
buses, "is [a] more realistic [solution]," he says.
To keep passengers informed about bus arrivals, AC has an additional plan - a partnership with NextBus, a company that tells passengers when the next bus is coming. So far, AC has purchased five NextBus signs, located at El Cerrito Del Norte and Richmond BART stations.
"The key to NextBus is believing that passengers are interested in controlling their time," AC Transit board member Greg Harper says.
For about $288,800 to date, NextBus transmits the arrival times of 35 buses, on routes 72, 72L and 73, to its web site and the five signs.
NextBus software also compiles on-time performance reports for the three routes.
At NextBus's headquarters in Emeryville, staffers can track the buses on real-time maps. "[Today] most of the vehicles are on time, 16 are early, 31 are at least 5 min late," Mike Smith, a NextBus Web designer, tells a visiting reporter. "You can also see that the 72L, here, is late over half the time …So what you might want to do is say - 'well, who's driving that vehicle?'"
Though Rudniski did not return calls about schedule adherence reports, Smith says he requested NextBus to compile monthly on-time reports for the San Pablo lines while waiting for SATCOM to get up and running. The lines are currently being tracked by both systems.
Officially, AC says a bus is off the timetable when it departs a stop either early or five minutes late. But knowing the frequency of off-schedule departures has, for years, been beyond AC's capability.
For instance, AC customer service reports recorded 20 late bus stop departures in August. But NextBus recorded 1356 late bus stop departures on the San Pablo corridor in only four days of that same month.
Mike Mills, AC Transit spokesman, says current AC reports estimate a 75 percent on-time rate. This statistic is based on the findings of 53 traffic checkers, deployed every three months to monitor schedule adherence from bus stops. They "provide a quarterly snapshot of how one line adhered to the published schedule on one day," he says, "But I don't know what that tells you."