High-tech system tracks MTA buses


December 14, 1992

The buses of Baltimore swim before the watchful eyes of Ron Jackson Sr. as green, yellow and blue triangles following purple lines.

Every 20 seconds, his computer screen is updated, and the triangles shift along their appointed rounds. The green are on time -- no problems there -- but the yellow ones are late, the blue are too early.

It is the latter two -- or heaven forbid, a red triangle (meaning there's an emergency) -- that will demand the dispatcher's attention.

Like an air-traffic controller, Mr. Jackson can see almost instantly where any one of his buses is at any given time in a 650-square-mile area around Baltimore. With its bird's eye view, his computer can tell him in what direction the buses are moving, and whether they are on schedule or not.

The veteran Mass Transit Administration dispatcher can even determine the name of each driver, figure out what shift he is working, and -- if there's an emergency -- listen in on what is happening aboard one of his buses.

Baltimore is the only city in the nation with such a capability. Called "Automatic Vehicle Location," or AVL, it was inaugurated four years ago by Westinghouse Electric Corp. under a $2.3 million federally-funded pilot program.

It uses Loran "C" technology, a radio triangulation system developed for the marine industry. Essentially, the Loran determines the longitude and latitude of a bus by radio transmissions and relays that information to a computer at MTA's Bush Division dispatch facility in West Baltimore.

The AVL computer has a complex task. It must figure out the buses' equivalent locations on a street map of a region extending from Columbia to Bel Air and then compare that information to the scheduled routes.

Since the Loran has an accuracy of 400 feet -- the length of some city blocks -- it's a tricky business. Complicating things further are the MTA's frequent route and scheduling changes.

The system can track only 50 buses, four supervisory vehicles and five routes. That's a fraction of the MTA's 62 routes and 860 buses, 400 to 500 of which are likely in service at any one time.

The remainder of the fleet is tracked the old-fashioned way. Dispatchers sift through volumes of schedule information to determine the likely location of a single bus at any given moment.

They must call up the driver by radio to find out anything more. (Don't laugh. Before 1971, the driver had to get off the bus and pick up a telephone to check in with headquarters.)

As marvelous as this technology seems, it has already become antiquated. Westinghouse is now installing a new system -- one that uses orbiting satellites -- for use by transit agencies in Denver and Milwaukee.

Westinghouse marketing executive Christopher A. Body says this new technology, which was developed for the military, is far more accurate: Each bus will have a receiver and a computer that can triangulate its position based on satellite signals.

The MTA and its sister agencies within the state Department of Transportation, the State Highway Administration and the Maryland Transportation Authority, have jointly applied for a $40 million grant to bring this new system to Maryland over the next five to seven years.

It's part of the national movement toward smarter transportation, known as Intelligent Vehicle Highway Systems. Here's how it might work:

* Your car has a --board-mounted computer that can tell you "real time" highway travel conditions. Collected by sensors embedded in the roads, among other things, the information is broadcast to your vehicle by a statewide traffic monitoring system.

* At major transit system transfer points, you can step up to a kiosk and find out when the next bus, subway train, light rail train or commuter train is due to arrive, perhaps even watch its progress on a computer map.

* Stranded in the city? You could pick up a telephone, call the MTA and find out the location of the nearest bus. The operator can then tell you whether it's delayed or early and how long you must wait.

* Emergency information, detailing accidents or other hazards, may be relayed to the electronic message signs along the highways or at transit stops.

A tie-up on the Jones Falls Expressway or at the harbor tunnels? The sign along the Baltimore Beltway might warn you so you could hop on the light rail.

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