Speed laws and impact

Key points

1. Unposted limits under favorable conditions: business district 20, alley 15, school zone 20 and residential district 25 mph.

   Source: Handbook p. 29

   “Business district, 20 mph.* Alley, 15 mph. * School zone, 20 mph.* Residential district, 25 mph.*”
   Alaska Driver Manual, Handbook p. 29

2. Speed limits on selected highways may be posted at 65 mph.

   Source: Handbook p. 29

   “Speed limits on selected highways may be posted at 65.”
   Alaska Driver Manual, Handbook p. 29

3. When conditions are less than ideal, drive at a careful and prudent speed.

   Source: Handbook p. 29

   “When driving conditions are less than ideal a person operating a motor vehicle on the highway shall drive at a careful and prudent speed”
   Alaska Driver Manual, Handbook p. 29

4. You may not drive faster than lets you stop within the assured clear distance ahead.

   Source: Handbook p. 29

   “A person may not drive a vehicle upon a highway at a speed greater than will permit them to stop within the assured clear distance ahead.”
   Alaska Driver Manual, Handbook p. 29

5. Do not drive so slowly that you block the normal flow of traffic.

   Source: Handbook p. 29

   “A driver may not drive at such slow speed as to hold back or block the normal and reasonable flow of traffic.”
   Alaska Driver Manual, Handbook p. 29

6. Fines are doubled in designated Traffic Safety Corridors.

   Source: Handbook p. 29

   “Fines for traffic offenses occurring in the corridor are doubled.”
   Alaska Driver Manual, Handbook p. 29

7. At 40 mph, impact and braking distance are 4 times greater than at 20 mph.

   Source: Handbook p. 28

   “The impact is 4 times greater at 40 mph than at 20 mph. The braking distance is also 4 times longer.”
   Alaska Driver Manual, Handbook p. 28

8. At 60 mph they are 9 times greater, and at 80 mph 16 times greater than at 20 mph.

   Source: Handbook p. 28

   “Triple the speed from 20 to 60 mph and the impact and braking distance are 9 times greater. Increase the speed to 80 mph and the impact and braking distance are 16 times greater than at 20 miles per hour.”
   Alaska Driver Manual, Handbook p. 28

9. Reckless driving, a willful disregard for safety, leads to license revocation.

   Source: Handbook p. 29

   “Reckless driving - A willful disregard for the safety of persons or property. Conviction will result in a license revocation.”
   Alaska Driver Manual, Handbook p. 29

Numbers to know

3 questions from the Alaska practice test

1. 1. In an unposted Alaska residential district, what default speed limit applies?

   1. 55 mph
   2. 15 mph
   3. 20 mph
   4. 25 mph
   Show answer

   25 mph. Alaska lists 25 mph as the default speed for a residential district when no sign establishes another limit. The 15 mph value belongs to an alley, while 20 mph applies to a business district and school zone in the same table. A driver should still lower speed when pedestrians, weather, or visibility require it, because the general speed law calls for a careful and prudent pace. Identify the district first, then verify whether local authorities have posted a change.

2. 2. What maximum speed may be posted on selected Alaska highways?

   1. There is no posted maximum
   2. 45 mph only
   3. 75 mph on every highway
   4. 65 mph
   Show answer

   65 mph. Alaska permits selected highways to be posted at 65 mph. This is a posted exception in the speed table, not a command to drive 65 mph everywhere and not proof that every highway has that limit. Conditions still matter, because the manual requires a careful and prudent speed that is reasonable for traffic, surface, width, and weather. Look for the actual sign, then reduce speed whenever conditions make the posted number unsafe.

3. 3. Under what conditions are Alaska’s listed statutory speed limits maximums?

   1. On every roadway regardless of posted signs or conditions
   2. On highways that are not otherwise posted and under favorable conditions
   3. Only inside residential districts during daylight
   4. Only when emergency vehicles are nearby
   Show answer

   On highways that are not otherwise posted and under favorable conditions. The manual introduces its listed speed limits as maximums for highways that are not otherwise posted and for favorable conditions. A posted sign can establish a different limit, and traffic, surface, width, or weather can require a lower careful and prudent speed. The residential-only choice ignores the manual’s broader roadway categories. The emergency-vehicle choice concerns a separate rule. Read the table as a ceiling for the stated conditions, then adjust below it whenever the road or weather reduces safety.

Source: the Alaska Driver Manual, Control of Vehicle, Following and Speed. This lesson is a plain English summary, not the law itself; where it differs, the manual and the statute govern. Last checked 2026-09-27.