(KRON) -- Caltrans is set to shut down westbound Interstate 80 from 5th to 15th streets in San Francisco from 11 p.m. Friday to 6 a.m. Monday to improve the roadway.  The closure means those heading west across the Bay Bridge into or through San Francisco will have a rough go of it.   “Coming into San Francisco, coming across the Bay Bridge, there will be heavy delays, but, several ways to avoid that is to use another bridge, San Mateo, Dumbarton, the Richmond San Rafael Bridge, or to use public transportation. It would be a great opportunity to use public transportation this weekend and avoid all of it,” said Caltrans spokesperson Lori Shepherd. During the 55-hour closure, Caltrans will be replacing the roadway surface with polyester concrete.  The agency says once complete this should make for a safer and smoother ride.  Those who must travel across the Bay Bridge to or through the city will be diverted off the freeway at 5th street.  Those wishing to continue south have a choice of two detours. They can either take Harrison Street and make a left on 6th Street and follow that to SB I-280, or they can continue on Harrison Street and make a left on 10th Street and follow that to SB HW-101. Additional information and a closure map can be found here. ...read more read less