A hybrid shuttle bus system began operating this month in Gatlinburg to carry visitors in and out of the Great Smoky Mountains National Park, an effort intended to reduce air pollution from auto emissions and reduce the amount of traffic and automobile noise at the crowded entrance to the park.

After months of planning, two hybrid electric-propane fueled micro-turbine buses were added to the city of Gatlinburg’s transit fleet for a six-month demonstration period.

The 22-seat shuttles were made possible by a $150,000 federal grant.

The National Park Service’s Green Energy Parks Program will monitor the success of the Gatlinburg demonstration project and determine whether such systems are viable for gateway communities at other national parks where traffic congestion and its impacts on the environment are growing concerns.

A March issue of National Geographic Traveler reported on a “Destination Scorecard” of 115 tourism destinations. The Great Smoky Mountains National Park got a poor rating due to the congestion, air pollution and unsustainable encroachment of gateway communities on the park setting. Gatlinburg was particularly blasted by the panel of international travel experts conducting the scorecard, citing it as an “ugly bathtub ring.”