More Utah County residents seem to be leaving their cars at home and riding the bus, the general manager of the Utah Transit Authority says.

Speaking to Provo City Council members Tuesday, John Pingree said UTA's weekday ridership in the county is the fastest growing area of service for UTA."The increase comes primarily from regular riders," he said. "A larger share are buying passes. The Provo/Salt Lake express bus is consistently full."

Weekday ridership in the area has increased from 2,000 in 1985 to 6,000 in 1989. UTA is presently building an $8 million facility to be completed in 1990 to handle a larger bus fleet.

The facility is designed to handle 50 buses initially with room for expansion to 100 buses. Federal funds will pay for 75 percent of the project, Pingree said.

Because of UTA's success, other cities are working to bring the bus service to their communities. American Fork, Pleasant Grove, Lehi and Lindon cities will all be voting in November on a sales tax increase to pay for bus service.

Additional routes to East Bay Business Center and Seven Peaks Aquatic Park are also in the works.

UTA's proposed light rail system will only go from downtown Salt Lake to 106th South, but Pingree said it is "logical to assume it would expand" to Utah County.