The Massey Tunnel will be closed to traffic on Friday and Saturday night.
The tunnel on Highway 99 will be closed to allow for testing of its fire suppression system and overhead lane control signals.
It will be closed in both directions on Friday and Saturday from 10 p.m. to 4 a.m.
Regular and commercial traffic will be asked to take a detour while emergency vehicles will be accommodated through the tunnel while work is being done.
A detour is available via Highway 91 and the Alex Fraser Bridge, according to B.C.’s transportation ministry.
Northbound traffic on Highway 99 should take Exit 16 Route 91 toward the Alex Fraser Bridge. Southbound traffic should take Exit 37 Route 91 toward the Alex Fraser Bridge.
Signs will be posted ahead of exits to advise drivers of the tunnel closure.
BC Ferries said the closure may affect travellers on some late-night sailings to and from the Tsawwassen ferry terminal.