Interstate 90 Floating Bridges in Washington

By | October 14, 2022


Lacey V. Murrow Memorial BridgeHomer M. Hadley Memorial Bridge
Spans Lake Washington
Lanes 3+2+3
Total length 2,020 meters
Main span 64 meters
Bridge deck height 9 meters
Opening 02-07-1940
Traffic intensity 145,000 mvt/day
Location Map

The Interstate 90 Floating Bridges, consisting of the Lacey V. Murrow Memorial Bridge and the Homer M. Hadley Memorial Bridge, is a United States pontoon bridge located in the city of Seattle. The bridges span Lake Washington.

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The river crossing consists of two separate bridges, with 3 lanes. The bridge connects the city of Seattle to the west with Mercer Island to the east. The bridge has 2×3 lanes plus a two-lane interchangeable lane. It is a relatively modern bridge with emergency lanes on all carriageways. The interchange lanes are for HOV users only, except for traffic to and from Mercer Island. The exchange lanes are therefore poorly utilized.

Lacey V. Murrow Memorial Bridge

The Lacey V. Murrow Memorial Bridge is the south bridge for eastbound traffic. The bridge is 2,020 meters long and a maximum height of 8.8 meters above the water. The bridge has 3 lanes of traffic and left and right emergency lanes. At both ends is a small arch bridge with a span of approximately 64 meters.

Homer M. Hadley Memorial Bridge

The Homer M. Hadley Memorial Bridge is the north bridge for westbound traffic. The bridge is 1,771 meters long and has 3 lanes and a 2-lane interchange lane. There is also a bicycle/footpath on the north side. The Homer M. Hadley Memorial Bridge is therefore a lot wider than the south bridge. On the west side, the bridge is partly double-decked, because the interchangeable lanes pass through a tunnel underneath each other.

  • Provides state overview of Washington and its alternative name as The Evergreen State


The first plans for a fixed connection across Lake Washington emerged in the early 1920s. The bridge was then constructed in 1.5 years between January 1939 and July 1940, and opened to traffic on July 2, 1940. This is the first Lacey V. Murrow Memorial Bridge. Construction cost $9 million at the time, including connecting infrastructure. It was a toll road for several years, the toll was removed in 1949.

To increase the capacity of the connection, the Homer M. Hadley Memorial Bridge was built in the late 1980s. It opened to traffic on June 4, 1989. This is shorter and wider, when opened it was the widest pontoon bridge in the world.

The Lacey V. Murrow Memorial Bridge sank in 1990 during maintenance work. The pontoons were filled with polluted water that was used to spray material from the bridge under high pressure. During a storm, the pontoons also filled with rainwater and the bridge slowly sank. The damage was $69 million. In 1993, the second Lacey V. Murrow Memorial Bridge was opened.

The bridge is named after Lacey V. Murrow, a World War II United States Air Force officer and second director of the Washington State Highway Department. The other bridge is named after Homer M. Hadley, the engineer who first proposed the connection in 1921.


The interchange with the HOV lanes is being converted into an East Link rail line that runs from Seattle to Redmond. For this, the HOV lanes are moved to the emergency lanes of the other lanes, so that the configuration is changed from 3+2+3 to 2×4. This will be the first light rail on a pontoon bridge. The conversion should be completed in 2020.

Traffic intensities

In 2012, 132,000 vehicles drove daily on the general purpose lanes and 13,000 vehicles on the interchange lane. The interchangeable lane has two lanes and is therefore used rather poorly.

Interstate 90 Floating Bridges in Washington