Arizona · Handbook chapter 8 · 4 min read

Chapter 8: Stopping, weather and night driving

Stopping distance and reaction time, Arizona dust storms, monsoon rain, hydroplaning, flooded washes, fog, snow and ice, headlight rules, highway hypnosis and wrong-way drivers.

Why this chapter matters

Arizona weather can change in minutes, from blinding dust to flash floods and mountain ice. Knowing how to react ahead of time, and how long stopping really takes, is the difference between a close call and a crash.

Stopping distance

Stopping distance depends on your speed, perception and reaction time, the pavement, your tires, brakes and the vehicle's weight.

• Average perception time is about 0.75 seconds and average reaction time another 0.75 seconds: about 1.5 seconds before you even start braking.
• Keep at least a 3-second following distance, and 6 seconds or more on slippery roads.
• Leave extra room behind large vehicles that block your view.

The open road

Rural highways have their own hazards: animals, farm equipment over a hill crest and water in low spots. Slow down for curves and hills that hide the road ahead.

Sun glare and wind

• Reduce glare with sunglasses, clean windows and the visor. With the sun behind you, oncoming drivers may not see you.
• Slow down in strong winds, especially crosswinds and when towing.
• When a truck or bus passes while you tow a trailer, move right in your lane and slow down, then speed up gently to keep the trailer straight.

Dust storms: Pull Aside, Stay Alive

If you see a dust storm, check traffic and slow down. Do not wait until you cannot see to pull off. In a severe storm:

• Drive completely off the highway and stop as far right as you can, not in a travel or emergency lane.
• Switch your lights off and lift your foot off the brake.
• Stay in the vehicle with belts buckled until it passes.

Rain and floods

• Be extra careful in the first 30 minutes of rain, when oil and grime make the road slick. Allow at least 6 seconds behind the car ahead.
• At about 50 mph in heavy rain, tires can lose all contact with the road; worn tires hydroplane at lower speeds. If you hydroplane, ease off the gas, do not brake, and hold the wheel steady.
• Do not cross flooded washes. Water can stall the engine, hide potholes and sweep the car away. Driving around flood barricades makes you liable for the cost of your rescue.
• After driving through water, test your brakes and dry them by driving slowly while gently pressing the pedal.

Fog, snow and ice

• In fog use low beams only, follow the edge markings and slow down. If you must, pull off, turn off your lights and wait.
• Snow and ice greatly reduce traction, so turn on your headlights, change speed and direction gently and slow down before stops and turns.
• Brake gently on ice. If the wheels lock, ease slightly off the brake, then reapply.
• Bridges and shady spots freeze first.
• Clear all snow and ice from windows and lights before driving; tires or chains help in winter.

Headlights and night driving

• Headlights are required from sunset to sunrise, and help in glare, rain and dust at any hour. Use headlights, not parking lights.
• Never drive faster than you can stop within the distance your lights show.
• Use high beams on highways only when no one is coming within 500 feet, and use low beams within 200 feet of a car you are following and on city streets.
• If an oncoming driver does not dim, glance toward the right edge of the road.
• Highway hypnosis: if you feel tired, pull over and rest. Fresh air and stopping every hour help.

Wrong-way drivers

• Wrong-way drivers are usually in the left or HOV lane and are often impaired.
• If one comes toward you, ease off the gas, make sure no one is beside you, steer away, then get to safety and call 911.
• If an overhead sign shows ALERT, WRONG-WAY DRIVER AHEAD, move safely to the nearest exit.