Deer on the Bridge, Ice on the Deck
At 7:05 a.m. in February the air temperature reads 28°F and light freezing drizzle is falling. You are eastbound at 55 mph on a two-lane road approaching a concrete bridge over a river; the deck looks darker and wetter than the pavement on either side. Your car has anti-lock brakes, front-wheel drive, and all-season tires with about 5/32 inch of tread remaining. As you reach the bridge, three deer step out from the left shoulder roughly 150 feet ahead and stop in your lane. On your right is a solid white fog line, a two-foot shoulder, and a guardrail. An oncoming minivan is about 400 feet away in the other lane.
1. What is the surface of the bridge likely to be, and what does that mean for how you approach it?
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That dark, wet-looking deck at 28°F with drizzle is a strong candidate for black ice.
- Bridges and overpasses freeze first. Cold air moves underneath the deck as well as over it, so the surface drops below freezing before the road on solid ground does.
- Black ice looks like wet pavement, not like snow or frost. The darker, glossier strip is the warning sign.
- Do your slowing before the bridge, on the pavement where you have some grip. Braking, steering, or accelerating on the deck is where control is lost.
Practically: if you had spotted the deck earlier, you would have come off the 55 mph before the expansion joint. At 5/32 inch of tread, your tires are legal but well short of good winter traction, so assume less grip than you expect.
2. At 150 feet with three deer in your lane, do you brake, swerve left, or swerve right? Reason it out.
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At 55 mph you cover about 80 feet per second, so 150 feet is under two seconds - this is a reflex decision you should have pre-made.
- Brake hard and straight. With ABS, apply firm, continuous pressure and hold it; do not pump the pedal, and do not release when you feel the pedal pulse. ABS lets you brake and retain some steering, but on ice it will not perform miracles.
- Do not swerve left. That is the oncoming lane with a minivan 400 feet away; a head-on at combined speed is far more lethal than hitting a deer.
- Do not swerve right. That is a two-foot shoulder and a guardrail; you will either be deflected back into traffic or through the rail.
Stay in your lane, brake in a straight line, and accept the impact if it comes. Hitting a deer while decelerating in a controlled lane is survivable; a head-on is not.
3. The deer runs off. Your car is drivable, airbags did not deploy, but the bumper and one headlight are smashed and you are stopped partly in the travel lane. What now?
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Being stopped in a live lane on an icy bridge is now the biggest hazard you face.
- Get the car out of the traffic lane if it will move - across the bridge to the shoulder if the bridge shoulder is too narrow to be safe, or to the nearest wide spot. Hazards on immediately.
- Call 911 and report the location, the lane, and that it was a deer strike. A deer crash is reportable; Michigan requires a crash report when there is injury or apparent property damage above the $1,000 threshold, and your insurer will want the police report.
- Do not stand between your car and traffic or behind it. Stay belted inside with hazards on if you cannot safely exit away from the roadway.
- Watch the surface as you move. Other drivers behind you are braking on the same ice, and the second crash at a crash scene is a real pattern.
If the car will not move, leave it, get everyone well off the roadway behind the guardrail, and call 911.