THERMAL, Calif. -

The public is invited to Tuesday's groundbreaking for a $29.5 million bridge over Union Pacific train tracks in Thermal.

   ``This overpass will greatly improve rail safety, response times by emergency vehicles, air quality and help make the Jacqueline Cochran Regional Airport more accessible and vital,'' Riverside County Supervisor John Benoit said.

   The 10 a.m. ceremony will be on the northwest corner of Grapefruit and Airport boulevards.

   Airport Boulevard is a one-lane street that serves Thermal, La Quinta and Coachella in each direction.

   The new bridge -- construction starts in March with completion set for July 2016 -- will have four lanes, said Benoit's spokesman, Darin Schemmer.

   Airport Boulevard, between Desert Cactus Drive and Polk Street, will be closed during the bridge's construction. Traffic will be detoured through Avenue 52 and Avenue 62 off Highway 86, Schemmer said.

   Every day, 71 freight trains pass through the eastern Coachella Valley, and the crossing arms at Airport boulevard are down for more than an hour.  Diverting traffic around the crossing would reduce idling time, thereby  improving air quality and public safety response times, according to Benoit's  office.