You’re driving down I-664, heading from Newport News toward Suffolk. The sky is huge. Suddenly, the road just... disappears.
One second you’re looking at the massive gray hulls of aircraft carriers at the Newport News Shipbuilding docks, and the next, you’re diving into the mouth of the James River. Most people call it the "MMM-BT." Or just "the Monitor Merrimac." It’s that weird, slightly terrifying, mostly beautiful stretch of concrete that connects the Peninsula to Southside Virginia.
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But honestly? Most drivers treats it like a chore. A 4.6-mile obstacle on the way to North Carolina or a commute to the shipyard.
They’re missing the point. This isn't just a bridge. It’s a $400 million engineering flex that sits directly on top of one of the most violent, world-changing spots in naval history.
The Battle Beneath Your Tires
If you think the name is just a mouthful of alliteration, you've gotta look down. About a mile from where the tunnel tubes sit on the riverbed, two iron monsters tried to kill each other in 1862.
The USS Monitor and the CSS Virginia (which everyone still calls the Merrimac, hence the bridge name) duked it out right here. It was the first time ironclad ships ever fought. Before this, ships were wood. After this, wood was basically kindling.
The Virginia was a beast—a floating iron barn roof with ten guns. The Monitor was weirder. It looked like a "cheese box on a raft." It had a rotating turret, which was revolutionary back then.
They pounded each other for four hours. Cannonballs literally bounced off the sides. It ended in a draw, but it changed how every navy on Earth built ships from that day forward. When you drive through the Monitor Merrimac Memorial Bridge Tunnel, you are quite literally driving through a graveyard of wooden naval strategy.
Why Does it Sink? (The Engineering Secret)
Ever wonder why they didn't just build a bridge the whole way? It would’ve been way cheaper.
The answer is the U.S. Navy.
The Monitor Merrimac is positioned right between the world’s largest naval base in Norfolk and the Newport News shipyard. If a bridge were to get bombed or collapse during a storm, it could block the channel. That would trap the Atlantic Fleet inside the harbor.
In a war, that's "game over."
By putting the road under the water, the channel stays clear no matter what happens to the surface structure. It’s built using something called the "immersed sunken tube" method.
Basically, they didn't dig a hole under the river. They built 15 massive concrete and steel tubes on land—each about 300 feet long. Then they floated them out, sank them into a pre-dredged trench, and sealed them together like giant Lego bricks.
A Few Wild Numbers
- 3 million: That’s how many four-inch square tiles line the tunnel walls.
- 6,000: The number of average-sized bathrooms you could tile with that same amount of ceramic.
- 1992: The year it opened, finally completing the "beltway" around Hampton Roads.
- 16.5 feet: The vertical clearance. (Pro tip: If your truck is taller than this, don't try it. You'll end up on the local news.)
The "Lesser" Tunnel?
Local drivers have a love-hate relationship with the Monitor Merrimac.
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If you live in Hampton Roads, you know the "Big Brother" is the Hampton Roads Bridge-Tunnel (HRBT) on I-64. That one is a nightmare. It’s older, narrower, and the traffic is legendary for all the wrong reasons.
The Monitor Merrimac was designed to be the relief valve. When it opened in April 1992, it felt like a miracle. Suddenly, you could get from Chesapeake to Newport News in 20 minutes instead of an hour.
But here’s the thing: it’s catching up.
When the MMMBT first opened, it saw maybe 30,000 cars a day. Now? It’s pushing way past that. During shift changes at the shipyard or when there’s a wreck on the HRBT, the Monitor Merrimac turns into a parking lot.
Still, the view is better.
Going northbound, you get this incredible "V" split where the James, Nansemond, and Elizabeth Rivers all collide. On a clear day, you can see the cranes of the port and the gray silhouettes of the fleet. It’s the most "Virginia" view in the state.
Survival Guide for the MMMBT
Look, nobody likes being stuck in a tunnel. It’s loud, the air tastes like diesel, and there’s always that one person who forgets how to maintain speed on the uphill climb.
If you’re planning to use the Monitor Merrimac Memorial Bridge Tunnel, you need to be smart about it.
First, check the "Overheight" sensors. VDOT has lasers that detect if a truck is too tall. If those lights start flashing, stop. Seriously. If a truck gets wedged in there, the whole region shuts down for hours.
Second, watch your speed on the descent. People naturally speed up going down into the hole, then slam on their brakes when they hit the bottom and realize they're doing 80 mph in a 60 mph zone. This "accordion effect" is what causes 90% of the traffic jams here.
Third, the wind. The bridge sections are exposed to the open water of the Chesapeake Bay's mouth. When a Nor'easter blows through, your car will feel like it’s being pushed by an invisible giant. Keep two hands on the wheel.
Is it Actually Safe?
People get nervous about "the tunnel part."
The walls look thin. You’re under millions of gallons of water. But the MMMBT is a fortress. It has 72 sensors in the pavement that check for traffic flow every 20 seconds. If a car stops, the Traffic Management Center knows about it almost instantly.
They’ve got 33 cameras watching every inch. There are even massive ventilation fans that can clear out smoke in minutes if there’s a fire.
The real danger isn't the water or the roof caving in. It's the "looky-loos." People slow down to look at the ships or the islands, and—bam—rear-end collision.
The Future of the Crossing
As of 2026, the traffic isn't getting any lighter. While the HRBT is getting a massive expansion (the largest project in Virginia history), the Monitor Merrimac is holding the line.
There's always talk about adding more lanes or a second tube, but for now, we're stuck with what we've got. It’s a 4.6-mile reminder of how much we rely on the water and how much we've spent trying to conquer it.
Next time you’re driving through, don't just stare at the bumper in front of you.
Think about the ironclads. Think about the 15 giant tubes sitting in the mud. And for heaven’s sake, keep your speed steady on the climb out.
Actionable Steps for Your Next Trip
- Download the 511 Virginia App: It’s the only way to know if there’s a "stalled vehicle" before you're already trapped in the queue.
- Time Your Commute: Avoid the 6:00 AM to 8:30 AM window and the 3:00 PM to 6:00 PM window. Shipyard shift changes are no joke.
- Check Your Tires: Blowouts in the tunnel are a nightmare. There’s no shoulder. You’re literally blocking a lane of interstate traffic until a tow truck arrives.
- Turn on Your Headlights: It sounds simple, but the transition from bright Virginia sun to tunnel yellow is jarring. Your eyes (and the driver behind you) will thank you.