- By Eric Kulisch
- Mar 04, 2001
NEXTBus Information Systems
For many commuters, mass transit is something to avoid. The hassle of connecting
with a bus, being exposed to the elements and jostling for position once
aboard is bad enough. And then, commuters can't count on buses to be on
In San Francisco, however, riders on the 22-Fillmore trolley bus line
don't have to deal with that uncertainty. Instead of craning their necks
over the curb for signs of their lift, they can view an electronic display
mounted on or near their shelter that tells them how many minutes until
the next bus arrives.
If a bus breaks down or is in an accident, that information is flashed
on the screen at the affected bus stops. In fact, commuters don't even have
to be there to get the information. They can check on the Internet before
they leave home or the office, or by using a wireless device.
"The 22-Fillmore was chosen because that line was considered one of
the poorest performing," said Michael Burns, general manager for the San
Francisco Municipal Railway.
The company providing San Francisco with this technology is appropriately
named NextBus Information Systems Inc. The company's system blends satellite-based
vehicle tracking, predictive software and wireless communications. The Emeryville,
Calif., start-up is running pilot programs in a number of cities, but San
Francisco is its largest test bed so far.
The Muni, as it is known, is embracing NextBus and other advanced traveler
information systems with fleet management features to improve service and
rider satisfaction. Giving passengers real-time information that can help
them negotiate their trips is a necessity for a city that places a premium
on mass transit, Burns said.
"The whole philosophy here is [toward] a transit-first environment,"
Burns said. "There are tremendous opportunities for getting people on transit
with this type of system."
"If you can put the systems in efficiently and effectively, you can
become more competitive with the automobile and hopefully increase ridership,"
said Larry Schulman, a former administrator for the Federal Transit Administration
and a consultant to the Intelligent Transportation Society of America.
The Muni is the seventh-largest public transit system in the United
States, with about 700,000 trips per day. It operates 140 electric streetcars,
350 electric trolley buses, 450 diesel buses, 38 cable cars and a historic
rail line with 30 cars.
The trolley buses are not the only vehicles getting technology to help
travelers navigate the city. Muni streetcars also have NextBus systems,
part of a two-year, $750,000 trial that ends this summer. And Muni has a
contract with Raleigh, N.C.-based Digital Recorders Inc. to provide its
Talking Bus system for new diesel buses. Talking Bus uses human-sounding
digital recordings and variable message signs to automatically announce
stops and routes. And 20 of the new buses will carry Swiss-made automatic
Global Positioning System technology is the foundation for both NextBus'
and Digital Recorders' components. Equipped with atomic clocks, the GPS
satellites transmit precise time and position information, which is picked
up by receivers on the vehicles.
What sets NextBus apart from other advanced traveler information systems
is its predictive software, which enables it to adjust to changing circumstances.
After installing the equipment, the company spends six weeks capturing
data from the buses, taking into account daily traffic patterns. The data
is used to build a baseline mathematical model of a vehicle's behavior.
The receiver sends a location report every 90 seconds through a wireless
modem to the company's servers in San Jose, Calif., and Dallas. Based on
the computer model, the software predicts when the vehicle will arrive at
its next stop. The model is constantly updated as the historical database
grows with time.
"We will be correct within a minute 95 percent of the time," said Jim
Maresca, NextBus' chief executive officer.
"It's been very accurate. We haven't had any problems with the predictions,"
That information is then relayed to the bus shelters, where passengers
can see an LED sign with the wait time for the next two or three buses.
The system can differentiate between separate lines operating on the same
street if the buses carry mobile data terminals, which code each vehicle.
Muni chose not to use the terminals for its pilot, Maresca said.
"If the bus is behaving as predicted, then the signs just keep counting
down," Maresca said. But if an accident or weather conditions delay the
bus and an adaptation is needed, the system sends a message to the sign
to change the prediction.
In the works are applications that can page or send e-mail to riders
when their bus is nearing, Maresca said.
"NextBus has probably been the most visible improvement we've made for
our customers in the last year to year-and-a-half," Burns said. "It's been
tremendously well received."
The voice annunciators also improve the passenger experience, he said.
Announcing each stop and route had been hard for Muni. Despite training
and disciplinary measures, bus drivers make announcements about 65 percent
of the time. The Talking Bus system will give riders "a high degree of certainty"
that their stop will be called, Burns said. This is especially helpful to
tourists and visually impaired riders, and when crowded conditions make
it difficult to see the coming stop, he said.
Although NextBus and Digital Recorders focus on the passenger, the information
they provide can help managers operate their fleets more efficiently and
provide faster response in emergencies.
With NextBus, managers know when to send another bus to finish a run
experiencing delays. They can send a message to drivers to skip stops or
slow down if they start to bunch up. And streetcar supervisors can track
the light rail vehicles when they leave the underground tracks to travel
on the street.
In addition to GPS-triggered voice announcements, Digital Recorders
captures vehicle diagnostic data on a memory card. Although Muni does not
get the data in real time, the GPS system allows time and location references
to be stamped on the data files. So, for instance, Muni managers can track
when the brakes and turn signals are used, doors open and close, and onboard
video surveillance tapes run, Digital Recorders General Manager Tanya Johnson
A standard Talking Bus system costs about $5,000, she said. NextBus
can outfit vehicles for five years at $7,000, including wireless charges.
The shelter signs are an additional $4,000 apiece.
A large-scale automatic vehicle location and computer-aided dispatch
system costs roughly $15,000 per vehicle, according to transportation industry
officials and U.S. government data.
But that's not the kind of system Burns said he wants. Most fleet management
systems communicate through expensive private radio networks. For a city
the size of San Francisco, that could cost about $50 million. Plus, there
is no guarantee that the system will be as reliable as promised because
the radio frequencies cannot handle that much simultaneous data transmission.
Rather than create a communications infrastructure it would have to
maintain, Muni can save time and money by taking advantage of commercial
wireless networks, Burns said.
"We are only 49 square miles," he said. "There is less of a need for
us to have some of the features that are contained in some of the larger,
more expensive systems."
Burns said he is pushing Muni to use the Internet as the common information
platform to keep costs under control. "What we really have to look at is
[this]: What's the information that we really need? People end up with huge
systems with a lot of information and then don't know what to do with it."
This year, Muni will issue bid requests for systems that can track vehicles
and provide up-to-date arrival times. Burns said he hopes to install the