Sixth Street Viaduct Replacement Project website. End of a Landmark: Sixth Street Bridge The 55-hour closure will be located “around the eastside of the viaduct construction site in Boyle Heights, closing a 2.5-mile section of US Rte 101 from the 10/101 split to the 5/10/101 interchange east of downtown Los Angeles.” The Los Angeles Bureau of Engineering shared this list of detours: When traveling N/B 5 from the Orange County area approaching the 5/10/101 Interchange : Exit to N/B 101 closed Exit to W/B 10 open Exit to N/B 5 open Primary Detour: N/B 710 to W/B 10 Secondary Detour: W/B 10 to N/B 110