For now it is more of a curiosity than a convenience, but the Port Authority today began to deploy a system that allows riders to track their buses' arrival with computers and mobile devices.

When the system is fully operational, riders will be able to view buses' locations on a map or display a page showing when the next bus will arrive at their stop. The system uses GPS technology.

The system is being pilot-tested on about 25 buses on the P1 East Busway-All Stops route. If the testing is successful, it will be expanded to other routes in coming months. It can be accessed on the Port Authority's website.

Allegheny County Executive Rich Fitzgerald said the plan calls for all bus routes to be online by the end of next year. Rail vehicles will be added after that.

The system was working well this morning, accurately forecasting the arrival of P1 buses at the Negley Station on the Martin Luther King Jr. East Busway. The route offers service about every four minutes during peak periods.

Mr. Fitzgerald said when the tracking system is fully operational, it might allow a rider to have an extra bowl of cereal in the morning, get more work done before leaving for the day or even avoid a case of frostbite on a cold, snowy day.

"This has been one of the main requests from riders for years," said Scott Vetere, director of service planning and evaluation for the transit agency.

First Published: August 21, 2013, 12:45 p.m.