The following ramps will also close for the duration of the closure:-The First Avenue South on-ramp to northbound State Route 509. -The Occidental Avenue South on-ramp to northbound SR 509. -The South Holden Street on-ramp to northbound SR 99. -Northbound SR 99 off-ramp to South Michigan Street. -Northbound SR 509/SR 99 traffic will exit at South Cloverdale Street and follow a signed detour during the weekend closures.