Buses that enjoy some of their own highways into Pittsburgh soon could be sharing them with taxis, vans and even commercial vehicles.

The Pittsburgh Transportation Group, which includes more than 300 Yellow cabs, says it would like to use the Port Authority's exclusive busways and is willing to pay for the privilege.

Yellow Cab Co. President Jamie Campolongo delivered the message to Dan Onorato yesterday when the county chief executive visited the company's North Side headquarters for lunch and "Driver Appreciation Day."

Mr. Onorato is interested. And so is the Port Authority: "We'd certainly be glad to take a look at that,'' said authority spokesman Bob Grove.

Mr. Campolongo said his cabs, airport limos, airport shuttle buses and ACCESS vehicles that run under Port Authority aegis could save time and money, improve transportation efficiency, save fuel and reduce pollution.

In turn, he said, Pittsburgh Transportation Group would consider paying an annual fee similar to the $600 per vehicle and $1 per trip that it pays for operating access at Pittsburgh International Airport.

The West Busway and Martin Luther King Jr. East Busway provide exclusive bypasses of the Fort Pitt and Squirrel Hill tunnels on the traffic-congested Parkway West and Parkway East, respectively.

Mr. Onorato said he's not only receptive to the idea but it fits into his plans to maximize use of transportation facilities as part of public-private partnerships.

"It sounds great in theory, but they'll have to be willing to pay," he said.

"That's what we need to find out first. The Transportation Task Force (that he formed earlier this year) is looking at the matter," not only for Public Utility Commission-regulated vehicles like taxis but also for private companies like UPS and FedEx.

Issues that would have to be settled besides fees that would provide a new source of revenue for the cash-strapped Port Authority include special operator training, liability insurance and possible new safety rules.

Currently, 383 buses a weekday use the West Busway and about 956 buses a day use the East Busway.

Mr. Campolongo said his company's drivers are already trained to authority standards and subject to some of the same rules, such as drug testing.

He estimated using the West Busway to and from the airport could cut an average of 20 minutes off rush-hour trips and reduce cab fares by 20 percent. The one-way taxi fare between the Pittsburgh Hilton and the airport is now about $32.50.

Mr. Campolongo said comparable time and money savings could be achieved if ACCESS vehicles could use the busways. The door-to-door, advance-reservation rides are the most heavily subsidized service in the authority's operating budget.

Mr. Campolongo said he approached authority officials about using the West Busway shortly after it was opened in 2000 but was told the extra traffic was not evaluated as part of an environmental impact statement needed to qualify for federal funding.

Instead, Pittsburgh Transportation Group vehicles that serve 85 percent of passengers at the "commercial curbs" at the airport are stuck in -- and contribute to -- the traffic jams on both sides of the Fort Pitt Tunnel.

"Going east is murder," Mr. Campolongo said, when cabs, vans and shuttles could be sharing the 9.3-mile East Busway to the eastern part of the city, Wilkinsburg, Edgewood and Swissvale.

He said the company's approximately 600 vehicles, ranging from stretch limousines to full-size buses, log more than 30 million passenger miles a year.

The taxis alone carry about 1 million riders.

Pittsburgh Transportation Group owns and operates Embassy Coach, Yellow Cab, Pittsburgh Transportation Co., Checker Cab Co. and Express Shuttle USA.

Mr. Grove of the Port Authority said sharing the South Busway is probably out of the question because it's already crowded with buses and light-rail vehicles in a narrow corridor through South Hills Junction and the Mount Washington Transit Tunnel.