Mount Baker Tunnel

The Mount Baker Tunnel or Mount Baker Ridge Tunnel carries Interstate 90 under the Mount Baker neighborhood of Seattle, Washington. It is actually a group of three tunnels that carry eight lanes of freeway traffic, plus a separate path for bicycles and pedestrians. The two originals are twin tunnel bores completed in 1940 and rehabilitated in 1993. The newest tunnel was built north of the original tunnels in 1991 and has a double-decked roadway with the bicycle/pedestrian path above the traffic lanes.
The entire tunnel is listed on the National Register of Historic Places (NRHP), ID #82004243. The east portals of the tunnel, with murals designed by artist James FitzGerald, along with the Lacey V. Murrow Bridge, are an official City of Seattle landmark.
The official length is 1,440 feet (440 m), though the perceived length while driving is closer to a 1 kilometre (3,300 ft) because of a cut-and-cover "lid" between the western portal and the beginning of the...