The next phase of work on Interstate 205 will cause more road closures than usual as construction crews build over Tracy’s main roadways.

Troy Bowers, spokesman for Caltrans’ Stockton office, said this is the week that the contractor, C.C. Meyers of Berkeley, will install the precast concrete girders that will hold up two new lanes in the middle of the freeway.

Girders are already in place at the Corral Hollow Road underpass, and on Tuesday, construction crews had cranes out at Tracy Boulevard ready to lower girders into the recently completed concrete bases. Work is also under way at MacArthur Drive to prepare that underpass for the expanded bridge.

Caltrans expects this work to continue through Thursday night, and since traffic delays are inevitable, crews will do nearly all the work at night. The main part of the work begins at 9 p.m. and ends at 6 a.m. There will also be work done on local on- and off-ramps, which will start at 7 p.m. each night.

Caltrans expects that construction crews will have to close lanes on the freeway and on Tracy’s main streets while construction is under way. In addition to traffic being reduced to single lanes, there will also be complete road closures of about 15 minutes at a time and some ramp closures.

Bowers said that the asphalt overlays on the westbound lanes are complete. C.C. Meyers will create similar overlays during the next several months on the eastbound lanes. That work is expected to be completed in August.

Another lane will be built on the center median in each direction, and Bowers said excavation for those lanes will begin in April. The bridge work, 22 structures in all, will continue through May of next year.

Caltrans expects the $103 million project to be completed by the end of 2009.