Idaho · Handbook chapter 9 · 6 min read

Chapter 9: Driving conditions and emergencies

Idaho 511, mountain and wildlife driving, open range, night driving, snowplows, fog, rain and hydroplaning, flash floods, winter driving and survival kits, skids, braking with and without ABS, breakdowns and crashes.

Why this chapter matters

Idaho weather and terrain change fast, from mountain passes to open range. The test asks how far your lights reach, how to handle skids and what the law requires after a crash. Learn 350 feet, 100 feet, 500 feet, two car lengths per 10 mph, 35 mph, 200 to 300 feet and $1,500.

Planning and mountain driving

• Dial 511 or visit 511.idaho.gov for road closures, roadwork, incidents and weather conditions.
• In the mountains, watch for curve and hill signs, keep right, use a lower gear on long downgrades, and never coast in neutral.
• On narrow roads with a blind curve, sound your horn as you approach.

Wildlife and open range

• Do not swerve for a small animal unless it is safe. Slow down for big game such as deer, elk and moose; they travel in herds, so expect more.
• If you cannot avoid an animal, hitting it may be the safest choice. Keep control before, during and after.
• Livestock being moved across a road have the right-of-way. On open range (most land outside cities and herd districts), animals may roam freely, even where there are fences. If you hit livestock on open range, the owner is not liable for your damage, and you may be liable if you were negligent.

Night driving

• About 90% of driving decisions depend on sight. Drive slowly enough to stop within the distance you can see: about 350 feet with high beams and 100 feet with low beams.
• Use headlights (not parking lights) from sunset to sunrise and whenever visibility is under 500 feet. Twilight and dawn are the most dangerous times.
• Leave more following distance and passing room, keep the windshield and headlights clean, and never wear sunglasses in low light.
• When oncoming lights glare, look toward the lower right of your lane. Dim your high beams for oncoming and followed vehicles and on lighted roads.
• If you must park on the shoulder at night, turn on flashers or parking lights.

Snowplows

• Stay two car lengths behind a plow for every 10 mph you drive.
• Pass only if absolutely necessary, never on the side where snow is spraying, and do not cut back in front of the blade.
• Do not brake suddenly in front of a plow, and do not abandon your car on the road if you can help it.

Fog, smoke, dust and rain

• Headlights are required in daytime when you can see 500 feet or less; use low beams.
• It is safest not to drive in fog, dust or heavy rain. If you must, slow down. If it gets too bad, pull off and stop; do not creep along or drive with flashers on.
• Do not use cruise control on wet or icy roads.

Rain and hydroplaning

• Roads are most slippery at the start of a light rain, when oil and water mix.
• Most tires grip up to about 35 mph on wet roads; by about 55 mph they may ride up on the water and hydroplane.
• To prevent it: slow down, avoid puddles, and keep tires inflated and replace them when worn.
• If you hydroplane: hold a straight line, ease off the gas, and do not brake or turn hard until the tires grip.

Flash floods

Idaho averages seven flash floods a year, usually during or right after thunderstorms. Six inches of fast water can knock you down and two feet can carry off a car. Never drive into a flooded road; turn around. If your car stalls in rising water, leave it and get to higher ground.

Winter driving

• Keep lights, tires, brakes, wipers, defroster and radiator in good shape, and fill the washer with non-freezing fluid.
• Clear all windows before you go, even for a short trip.
• Start slowly to test your grip, and begin slowing three times sooner than usual for turns and stops.
• Watch for ice on bridges, overpasses and shaded spots. Use chains on very slippery roads.
• Carry a winter kit: flashlight, first aid kit, blanket, gloves, cap, sand or cat litter, shovel, water, jumper cables, flares, food, phone charger and a bright cloth.
• If you get stranded in heavy snow, stay with your vehicle, keep the exhaust pipe clear if you run the engine, and tie a bright cloth to the antenna.

Skids and quick stops

• In a skid, do not panic and do not brake. Take your foot off the gas and steer in the direction of the skid: if the rear slides right, steer right.
• With ABS: press the brake hard and steadily; do not pump. The pulsing and noise are normal. ABS keeps steering but does not shorten stops.
• Without ABS: brake as hard as you can without locking. If the wheels lock, let up, then press again.

Car trouble

Pull completely off the road, turn on flashers and raise the hood. If you cannot get off the road, stop where drivers behind can see you, not just past a hill or curve. Place flares 200 to 300 feet behind the car.

Avoiding and surviving crashes

• You can steer, brake or accelerate to avoid a crash. Steering away is often better than braking if you cannot stop in time.
• If hit from behind, press your head against the head restraint. If hit from the front, protect your face with your arms.
• Oncoming car in your lane: slow, flash lights and sound the horn, and pull to the right, never left. If you must hit, try for a glancing angle.
• Blowout: hold the wheel tightly, keep straight, ease off the gas, and brake only once you have control.
• Wheels off the pavement: hold straight, ease off the gas, brake gently, and steer back only when it is safe, without oversteering.

Crashes and the law

• Stop near the scene without blocking traffic. Idaho's Quick Clearance law requires drivers in a crash on an interstate or major divided highway with no death or injury to move their vehicles to the shoulder, median or emergency lane.
• Help the injured. The Good Samaritan law protects you if you act in good faith, but do not move an injured person unless there is a danger such as fire or you are trained.
• Report to police any crash with an injury or more than $1,500 of property damage, and exchange names, addresses, license numbers and insurance details.
• If you hit an unattended vehicle, try to find the owner; if you cannot, leave a note with your name and phone number.
• If police and medical help are already at a crash you come upon, keep moving as officers direct. If you are first, stop, call 911 and help if you can.