Wrapped on all sides in colorful vinyl, two VINE buses are turning heads this summer.

The buses tout the Bay Area’s Spare the Air program, said Deborah Brunner of the Napa County Transportation and Planning Agency. Motorists are encouraged to take transit on days when air pollution is high.

The Bay Area Air Quality Management District and the Metropolitan Transportation Commission paid to turn two buses into mobile billboards, Brunner said. Buses throughout the Bay Area were similarly wrapped, she said.

The agency selected two clean energy buses that run on compressed natural gas. They typically run on Route 10 between Calistoga and Vallejo, Brunner said.

The vinyl will remain as long as it continues to look good, Brunner said. Vinyl can last a year. It comes off without harming the paint, she said.

NCTPA decided not to wrap the windows so as to not degrade the views of riders, she said.

During the first four weekday Spare the Air days this summer, rides on the VINE and other Bay Area transit systems will be free./Register