Construction of an enormous railroad overpass in Colton, Calif., remains on a scheduled late 2011 start, as officials finalize details of a design agreement, The Press-Enterprise reports. Members of San Bernardino Associated Governments are poised to agree to the contract for design of the Colton Crossing at the agency's monthly meeting.

The agreement between county transportation officials, Union Pacific and BNSF is one of many agreements needed for the long-sought and highly-debated project. The crossing will untie a decades-old train crossing where Union Pacific's east-west tracks meet BNSF's north-south line.

Both railroads and state officials have pressed for building a 1.4-mile-long overpass to separate the tracks. Putting the Union Pacific tracks above the BNSF line would allow both railroads to use the tracks freely, and eliminate waits as crossing trains pass.

More than half of the $202-million project is paid for with public funds. In March, officials announced $33.8 million from the federal stimulus program was awarded to the project. In May, the California Transportation Commission directed $91.3 million from California's Prop. 1B transportation bond program that voters approved in 2006 to the crossing.

But those approvals came with some concessions from the railroads, after state officials balked at the benefit the public was receiving from a private project set to receive millions of government dollars. More commuter trains slots will be available in coming years to ferry commuters from the Inland area to Los Angeles on Metrolink trains as part of the master project agreement approved in May by state officials

Because of the public money, county transportation officials are overseeing the project, but any costs associated with it will be paid by the railroads, according to the design agreement.

Engineering and design of the overpass is expected to take until July 2011. Construction could begin three or four months after that, said Union Pacific spokesman Aaron Hunt. If the schedules hold, the overpass will be completed in late 2014, Hunt said.