Indiana State Police issued the warning plainly during a January storm on I-65: although the roads look clear, black ice is causing dangerous conditions.
That morning the bridge at northbound mile marker 247 near Crown Point was described as completely frozen. Multiple truck crashes followed, two lanes closed, and more crashes occurred at I-65 and Ridge Road in Merrillville.
Black ice is dangerous precisely because it does not look like ice. It looks like wet pavement, and often like dry pavement. Understanding where it forms is more useful than any general advice about slowing down.
Where Black Ice Forms First
The Indiana Department of Transportation identifies the predictable locations. Learn these four and you have most of the risk covered.
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Bridges and overpasses. Air circulates above and below the deck, so they freeze before the roads leading onto them. This is why a bridge can be frozen while the highway approaching it is merely wet.
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Intersections. Repeated braking and acceleration polish the surface.
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Off-ramps. You are decelerating and turning simultaneously, which is the worst combination on a low-traction surface.
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Shaded areas. A stretch under trees or beside a tall building holds ice long after the exposed road has cleared.
There is a further wrinkle worth knowing. Roadways warm more slowly than the surrounding air, so ice can persist on the pavement even after the thermometer climbs above freezing. Warming weather is not the same as a safe road.
The Four-Wheel Drive Illusion
This is the misconception that puts SUVs in ditches, and INDOT addresses it directly.
Four-wheel drive may get you going faster, but it will not help you stop sooner.
All-wheel drive distributes power to help you accelerate on a slick surface. It does nothing for braking or cornering, because those depend entirely on the grip between four tires and the road. Once traction is lost, a four-wheel drive vehicle slides exactly like anything else, and it does so carrying more weight.
Drivers who feel confident pulling away from a stop often carry that confidence into a corner where it does not apply.
The First Storm Is Worse Than the Worst Storm
Months of driving in mild conditions produce complacency. When roads first turn slick, everyone on the road is relearning how to drive at the same time.
INDOT flags the first snow or ice event specifically, and the pattern is visible in the data from real storms. Indiana State Police received nearly 200 calls for service in northwest Indiana during one such day, more than 50 of them for crashes.
A refreshingly honest note from the same event, after a second round of snow: "everything that melted froze again and it was worse the second time than it was the first time."
Refreeze is the underappreciated hazard. A partial thaw followed by a temperature drop produces worse conditions than the original snowfall.
What to Actually Do Differently
Increase following distance substantially. Stopping distances lengthen dramatically on ice, and four seconds in dry conditions is not enough on a slick road.
Turn off cruise control. On a slippery surface it can accelerate into a skid rather than easing off.
Clear the entire vehicle, not a porthole. Snow left on the roof slides onto your windshield under braking. Clear windows, lights, brake lights, and signals so you can see and be seen.
Give plows room. INDOT plows every interstate, US route, and state road every two to three hours during a storm. The road behind a plow is better than the road in front of it.
Check conditions before leaving, through INDOT's TrafficWise site or 1-800-261-ROAD.
And know when not to go. INDOT's own framing is "Ice and Snow, Take it Slow, or just don't go." A trip you postpone is not a trip you crash on.
Frequently Asked Questions
Where does black ice form first in Indiana?
Bridges and overpasses freeze first because air circulates above and below them. Intersections, off-ramps, and shaded areas are the other common locations.
Does four-wheel drive help on ice?
It helps you accelerate, not stop. Braking and cornering depend on tire grip, so a four-wheel drive vehicle slides the same as any other once traction is lost.
Can there be ice when temperatures are above freezing?
Yes. Pavement warms more slowly than the air, so ice can remain on the road surface after the thermometer rises above 32 degrees.
Why is the first snow of the season so dangerous?
Drivers have spent months in mild conditions and have not adjusted. INDOT identifies the first snow or ice event as a particular risk period.
Should I use cruise control in snow?
No. On slippery surfaces cruise control can apply power at the wrong moment and accelerate into a skid.
The Bottom Line
The bridge is frozen before the road is. Four-wheel drive does not help you stop. Pavement stays icy after the air warms. And the first storm of the season catches more drivers than the worst one.
Check conditions before you leave, lengthen your following distance, clear the whole vehicle, and postpone the trip if the answer is obvious.
Hazard recognition in poor conditions is core defensive driving. ABetterDriver offers the Indiana Bureau of Motor Vehicles approved Driver Safety Program fully online for $28.95, self-paced, with completion reported directly to the BMV for a 4-point credit.
