Smoke. That’s usually the first thing you notice before the brake lights start blooming like red flowers across the horizon. If you’ve been stuck in traffic behind a fire on I-90, you know the drill. It’s frustrating. It’s slow. Honestly, it’s kinda scary when you’re boxed in by concrete barriers with nowhere to go while sirens wail somewhere up ahead.
Interstate 90 is the longest highway in the United States. It stretches over 3,000 miles from Seattle to Boston. Because it crosses mountain passes, dense forests, and dry plains, the "why" behind a fire on this specific road changes every fifty miles. Sometimes it’s a brush fire sparked by a tossed cigarette in Eastern Washington. Other times, it’s a semi-truck’s brakes overheating on a steep grade in the Berkshires.
Whatever the cause, the result is the same: total gridlock.
Why a Fire on I-90 Causes Such Absolute Chaos
When a fire breaks out on an interstate, the Department of Transportation (DOT) doesn’t just close a lane. They often shut down the whole side of the highway. Why? Because of visibility. Smoke is a killer. It’s not just the heat or the flames; it’s the fact that a wall of white or grey smoke can drop visibility to zero in seconds. People slam on their brakes. Chain reactions happen.
Emergency crews need what they call "working room." If a car catches fire, the local fire department has to park their massive engines in a way that protects the firefighters from oncoming traffic. This creates a "lane taper" that can back up traffic for ten miles. I’ve seen it happen in the Snoqualmie Pass area where a single car fire turned a two-hour drive into a six-hour ordeal.
There’s also the pavement to consider. Intense heat from a vehicle fire—especially a magnesium engine block or a tanker truck—can actually delaminate the asphalt or spall the concrete. Engineers from agencies like WSDOT or MassDOT have to inspect the road surface before they let you drive over it again. If the structural integrity is shot, you aren't going anywhere.
The Real Risks of Roadside Brush Fires
Dry grass is basically fuel. In states like Montana, South Dakota, and the eastern half of Washington, the land flanking I-90 is often a tinderbox.
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- Dragging chains: A trailer chain hitting the pavement creates sparks. Those sparks fly into the median. Boom. You’ve got a five-acre fire.
- Blown tires: When a tire shreds at 70 mph, the metal rims hitting the road send out a shower of heat.
- Catalytic converters: If you pull over into tall, dry grass because your engine is running hot, your catalytic converter (which can reach 1,200 degrees) will ignite the vegetation instantly.
It's a weird irony. The very road that connects the country acts as a giant fuse for wildfires. In 2024 and 2025, we saw several instances where I-90 had to be closed because the Vantage Bridge area was surrounded by fast-moving grass fires. It wasn't that the road was burning; it was that the fire was jumping the highway.
Dealing with the "Rubbernecking" Effect
We all do it. You finally get past the flare-up, and what happens? Everyone slows down to look. This is the "phantom traffic jam." Even after the fire on I-90 is extinguished and the scorched shell of the vehicle is towed away, the ripple effect of people braking to look at the "black spot" on the road can persist for hours.
Traffic experts call this a backward-traveling wave. If one person taps their brakes to look at a burnt-out semi, the person behind them taps harder. Eventually, five miles back, someone comes to a dead stop.
How to Check Real-Time Closures Without Losing Your Mind
Don't rely on the big maps apps alone. They're great, but they often lag by 10 to 15 minutes. By the time your GPS turns red, you’re already stuck.
Instead, look for the State Patrol's Twitter (X) feed or the specific DOT "Real-Time Travel" map for the state you’re in. For example, Washington’s WSDOT app is notoriously better than Google Maps for mountain pass fires. In Illinois, the Tollway's own alerts are the way to go.
If you see "Active Fire" or "Emergency Response" on those overhead digital signs, believe them. Don't think you can "beat it." You can't. Take the next exit. Find a diner. Wait it out.
What to Do if You Encounter Fire While Driving
This is rare, but it happens. If you see flames licking the side of the road or smoke crossing the lanes:
- Windows up, AC off: You don't want to suck smoke or embers into the cabin.
- Lights on: Turn on your full headlights and hazards so people behind you don't rear-end you in the haze.
- Don't stop in the lane: If you can't see, people behind you can't see either. If you stop in the middle of the road, you’re a sitting duck for a semi-truck.
- Listen to the radio: Local AM stations still carry emergency broadcast info that can be more specific than a phone app.
The Long-Term Impact on Infrastructure
Fire damage isn't just about the immediate mess. After a major incident, especially one involving hazardous materials or large fuel spills, the soil around I-90 often has to be remediated. This means more construction crews, more orange cones, and more "reduced speed" zones for weeks after the fire is out.
The heat can also damage the steel reinforcements inside bridge decks. If a fire happens under an overpass—which we’ve seen with homeless encampments or truck accidents—the bridge might be closed for a "stress test." This is what happened in various urban corridors of I-90 in cities like Chicago or Cleveland. It’s a massive headache for commuters.
Staying Safe and Prepared
Look, I-90 is a lifeline, but it’s a temperamental one. Fires are a reality of high-speed travel and changing climates. The best thing you can do is stay informed and keep your car maintained so you aren't the one causing the next backup.
Next Steps for Your Trip:
- Check the "State DOT" dashboard: Before you leave, search for the specific DOT site for your state (e.g., "NYSDOT Travel Map") rather than just trusting your phone's default GPS.
- Pack an emergency kit: Always keep three gallons of water and some non-perishable food in the trunk. If a fire shuts down the highway, you could be sitting there for four hours without a bathroom or a vending machine.
- Monitor your gauges: If your "Temp" needle starts climbing, pull over in a cleared, paved area immediately. Don't wait for the smoke.
- Download offline maps: If you're heading through the rural stretches of I-90 in Montana or Wyoming, cell service will drop. If a fire forces a detour, you'll need those offline maps to find the backroads.