Alaska · Handbook chapter 5 · 6 min read

Chapter 5: Speed, following distance and vehicle control

Alaska's speed limits and the basic speed law, the four-second following rule, braking distance, backing, signaling, and the duty to pull over for a line of traffic.

Why this chapter matters

Speed limits, following distances and signaling distances are among the most tested figures. Learn 15, 20, 25 and 55 mph, four seconds (six or more in bad conditions), two seconds as the legal minimum, 100 feet for signals and five vehicles behind you.

Keeping control

You have control of your vehicle when you can steer, regulate your speed and slow or stop whenever you need to. You must control yourself first: lack of sleep, strong emotions and distractions all weaken your control. The manual notes that more fatal crashes happen in daylight, on dry roads, in clear weather and in sound vehicles than in any other conditions: the driver is the biggest single cause of crashes.

Every driver must take care to avoid hitting pedestrians (people walking or riding bicycles), animals and other vehicles. Slow down and be ready to stop near:

1. People walking or biking on or along the road.
2. Animals being led, ridden or driven on or along the highway.
3. Railroad crossings, intersections, bridges, sharp turns, curves and steep downgrades.
4. Red reflectors, red flags or flares.
5. Orange flags and signs, which mark a high hazard area such as road work.

Backing

Do not rely on your mirrors alone. Hold the top of the wheel with your left hand, twist your upper body to the right and look back through the rear window. Steer toward the side you want the rear of the car to move to, back slowly and keep looking all around. Yield to vehicles and people, and keep your speed to no more than about 5 mph. It is illegal to back on a controlled access highway or its ramps unless police, fire or flag personnel direct you.

Following distance

The law says you may not follow more closely than is reasonable and prudent for your speed, the traffic and the road.

The four-second rule

Watch the vehicle ahead pass a fixed point, then count "one thousand and one" up to "one thousand and four." If you reach the point before you finish, you are too close.

• The manual recommends four seconds; Alaska regulation 13 AAC 02.090 requires at least two seconds.
• When towing a trailer or on wet or slippery roads, increase it to six seconds or more.
• The same count at night tells you whether you are overdriving your headlights.

Other ways to avoid rear-end crashes: watch for brake lights and cover the brake, notice a shrinking gap, judge whether distant vehicles are moving by comparing them with fixed objects, and look for trouble developing ahead of the driver in front.

Avoiding being hit from behind

Keep your brake lights clean and working, and flash them when you are about to stop. Know what is behind you, keep the rear window clear of frost and snow, signal early, slow down gradually, and keep pace with traffic within the limits.

Pulling over for traffic behind you

You also have a duty to yield to faster traffic. On a two-lane road outside an urban area, you must pull over safely when five or more vehicles are lined up behind you (AS 28.35.140). You are never required to drive at the maximum speed.

Speed, impact and braking distance

Striking power and braking distance grow much faster than speed:

It takes about three-quarters of a second to react and step on the brake. At 50 mph your car travels about 55 feet in that time, and then perhaps 160 feet or more after the brakes go on.

Speed limits

Where no other limit is posted, these are the maximum speeds in good conditions:

Local authorities or the state can change these limits, and some highways are posted at 65 mph.

The basic speed law

When conditions are less than ideal, drive at a careful and prudent speed that suits the traffic, the road surface, the road width and the weather. You may never drive faster than lets you stop within the clear distance you can see ahead.

• Do not drive so slowly that you block the normal flow of traffic.
• On multi-lane highways, use the right lane if you drive slower than others, except to pass.
• Reckless driving, a willful disregard for the safety of people or property, leads to license revocation.
• Fines are doubled in designated Traffic Safety Corridors.

Signaling

Give a hand or turn signal continuously during the last 100 feet before you turn, and from farther back when traffic or high speeds call for it. Also signal before stopping or slowing suddenly.

• Use hand signals when bright sun or a line of cars behind you could hide your signal lights.
• Alaska law requires you to cancel your turn signal after the turn. A forgotten signal can tempt another driver to pull out in front of you.
• Keep signal lights clean and free of dirt, ice and snow.

Towing

Towing two or more vehicles at once is allowed only when the vehicle doing the towing is over 15,000 pounds, has at least three axles, and both it and the vehicles behind it have air brakes.