New York state highway workers are constructing a 41-foot plastic bridge that is expected to help save on future maintenance costs. The plastic bridge will be about double the price of a conventional bridge, but advocates say the long-term savings outweigh the up-front costs.

The Livingston County Highway Department started work late last month on the $600,000 project about 20 miles south of Rochester in Avon. Unlike traditional bridges built with concrete and steel, the new bridge will have beams made with fiber reinforced plastic, a combination of fiberglass and plastic.

The beams, made of the same substance as automobiles and boats, but thicker, are designed to hold up to weather changes and not corrode. The bridge is expected to last 75 years with little maintenance, while a conventional bridge would need repairs within 20 years.

Plastic bridges weigh about one-quarter of a conventional bridge, making them easier to install and cutting traffic delays and labor costs. The road surface will be made of concrete; the only difference being the beams underneath.

About 40 bridges have been constructed nationwide with plastic composite.