How long is the Monitor-Merrimac Memorial Bridge-Tunnel in Virginia?

The Monitor-Merrimac Memorial Bridge-Tunnel (MMMBT) is a 7.4-kilometer (4.6-mile) four-lane bridge-tunnel crossing the James River at the mouth of Hampton Roads in Virginia, USA. Carrying Interstate 664 (I-664), the facility links Newport News on the Virginia Peninsula with Suffolk on the South Hampton Roads mainland. It's one of the most spectacular bridges in the world.

Monitor-Merrimac Memorial Bridge-Tunnel
Road facts: Monitor-Merrimac Memorial Bridge-Tunnel
Location Hampton Roads / James River, Virginia (USA)
Route Designation Interstate 664 (I-664)
Total Length 7.4 km (4.6 miles) shore-to-shore
Tunnel Length 1,455 m (4,776 ft / 0.9 miles) underwater segment
Structure Type Low-slung concrete trestles, two artificial islands, and immersed tube tunnel
Opening Date April 30, 1992
Toll Facility Toll-free crossing
Key Hazards Gale-force crosswinds on trestles, tunnel gridlock, sudden rain flooding at portal ramps

Where is the Monitor-Merrimac Memorial Bridge-Tunnel located?

The bridge-tunnel spans the broad estuary of the James River in southeastern Virginia. Carrying four lanes of I-664, it serves as a western bypass around the core of Hampton Roads, connecting the Peninsula cities with the Southside region.

How is the Monitor-Merrimac Bridge-Tunnel structured?

Opened on April 30, 1992, the 4.6-mile crossing consists of 3.7 miles of low-slung concrete trestle bridges and elevated ramps leading onto two man-made portal islands. Between the islands, traffic dives into a 1,455-meter (4,776-foot) four-lane immersed tube tunnel buried beneath the main shipping channel of the James River.

Why was the bridge named Monitor-Merrimac?

The crossing is named after the historic Civil War Battle of Hampton Roads fought on March 8-9, 1862, directly over the water where the bridge-tunnel now stands. It marks the site of the world's first battle between ironclad warships: the USS Monitor and the CSS Virginia (built on the hull of the USS Merrimack). 

Why does I-664 plunge underwater into a tunnel?

The tunnel section keeps the surface shipping channel clear for military vessels operating out of Norfolk Naval Station and commercial cargo traffic serving the Port of Virginia. Constructing a high-level fixed bridge would have created a permanent navigation hazard for aircraft carriers and cargo ships entering the river.

What are the hazards on the Monitor-Merrimac Bridge-Tunnel?

Strong coastal wind gusts sweep across the open trestles during Atlantic storms, leading to high-profile vehicle restrictions. Heavy downpours trigger water pooling on the steep portal approaches plunging into the tunnel, while sudden traffic bottlenecks inside the twin tubes cause frequent rear-end collisions during peak rush hours.
Road suggested by: Brianna Shari