Seattle's Department of Transportation advises commuters that a section of Broad Street between Interstate 5 and the Seattle Center will permanently close to traffic on Sunday evening.
While necessary to complete major roadway improvements, the closure is expected to create significant traffic disruptions along the Mercer Corridor.
Motorists are advised to use alternate routes and expect lengthy travel delays due to the Broad Street closure and drivers adjusting to two-way operations on Mercer Street.
Beginning with the Monday morning commute, Broad Street will permanently close to traffic between 9th Avenue North and 5th Avenue North as Mercer Street opens for the first time to two-way traffic connecting I-5 to lower Queen Anne.
The permanent closure of Broad Street is necessary to allow for additional construction associated with the Mercer Corridor Project and the state DOT's Alaskan Way Viaduct replacement project.
The closed portion of Broad Street will be used to widen Mercer Street in its final configuration of three lanes in each direction between I-5 and 5th Avenue North and for the Highway 99 North Access Project, which will build connections onto adjacent surface streets from the future bored tunnel.
Beginning Monday morning, Mercer Street will be open to two-way traffic between I-5 and Elliott Avenue West. All commuters are advised to plan ahead and use alternate routes where possible as the number of vehicles using eastbound Mercer Street will increase, officials said
Changes through the corridor will include:
Mercer St. will have two lanes in each direction between Queen Anne Ave. N and 9th Ave. N.
Access to Seattle Center and Queen Anne will be a direct route via westbound Mercer St. from I-5.
Roy St. will have one lane in each direction between Queen Anne Ave. N and 5th Ave. N.
Queen Anne Ave. N will have one northbound lane and two southbound lanes between Roy and Mercer Streets.
Left turns from westbound Mercer St. onto southbound 5th Ave. N will be available.
Left turns from eastbound Mercer St. onto northbound Dexter Ave. N will not be allowed for approximately one year.
Access to northbound Highway 99 from eastbound Mercer St. will be via southbound Dexter Ave. N onto westbound Thomas St.