By Galen Moore, Boston Now

3/3/08 - Jeremiah Scharf had every bus commuter's constant complaint on his lips as he waited for the bus on a frozen sidewalk: you wait 20 to 25 minutes, then two or three buses arrive in a pack. "That happens all the time," said Scharf, 37.

Now, 14 MBTA employees are working to stop that. Using a GPS system, dispatchers are tracking buses on seven routes, so they don't bunch in traffic.

"It's almost a physical force that causes them to gravitate together," explained bus operations chief David Carney. Fixing that is difficult, he said. Holding back a bus can prevent bunching, but it delays riders already on board.

Eventually, the GPS systems will be on every route. Several commuters interviewed last week said they have seen small improvements on the No. 39 bus since GPS was deployed last year. But technology can't part the traffic.

Bekka Lee, 25, said she doesn't worry if she misses the 39. "At rush hour I can chase it and catch it," she said.

Still, route managers hope GPS will prevent major delays. Before, their only information came by radio from inspectors on the street. Now, they have a better view of the situation, Carney said. "Think of the football coach who's up in the box looking down."

Where GPS is

GPS is now deployed in various pilot stages on Bus Nos. 1, 15, 22, 23, 32, 39 and 66.

'Celling' bus futures

It's a long way off, but eventually bus GPS data may pop up on your cell phone. T technocrats are considering a program that would let you text your stop number and receive a message back showing how long until the next bus.