Speed laws

Key points

1. A frontal impact at 35 mph is one third more violent than one at 30 mph.

   Source: Handbook p. 86

   “A frontal impact at 35 mph, for example, is one-third more violent than one at 30 mph.”
   Louisiana Class D and E Driver's Guide, Handbook p. 86

2. Speed limits are posted for ideal conditions.

   Source: Handbook p. 86

   “Remember that speed limits are posted for ideal conditions”
   Louisiana Class D and E Driver's Guide, Handbook p. 86

3. The General Speed Law: you must not drive faster than is reasonable.

   Source: Handbook p. 87

   “The General Speed Law is that you must not drive at a speed greater than is reasonable.”
   Louisiana Class D and E Driver's Guide, Handbook p. 87

4. Do not drive faster than the posted maximum or slower than the posted minimum.

   Source: Handbook p. 87

   “You must not drive faster than the posted maximum limit. You must not drive slower than the posted minimum limit.”
   Louisiana Class D and E Driver's Guide, Handbook p. 87

5. Slow down on streets near schools and playgrounds and at school crossing signs when children are present.

   Source: Handbook p. 87

   “On streets near schools and playgrounds and at locations marked with a "school crossing" sign when children are present.”
   Louisiana Class D and E Driver's Guide, Handbook p. 87

6. Racing or any speed contest on a public road is unlawful.

   Source: Handbook p. 87

   “It is unlawful to participate in any race, speed contest or speed exhibition of any public street or road in this state.”
   Louisiana Class D and E Driver's Guide, Handbook p. 87

7. The interstate maximum is 70 mph unless otherwise posted.

   Source: Handbook p. 100

   “Remember that the maximum speed allowed is 70 miles per hour unless otherwise posted.”
   Louisiana Class D and E Driver's Guide, Handbook p. 100

Numbers to know

Recognize these signs

3 questions from the Louisiana practice test

1. 1. When may a driver travel at the maximum speed shown on a Louisiana speed limit sign?

   1. Whenever the driver is late
   2. Only in ideal driving conditions
   3. Only when following another vehicle
   4. Regardless of rain or fog
   Show answer

   Only in ideal driving conditions. A posted maximum speed is intended for ideal driving conditions. Rain, fog, slippery pavement, snow, ice, or poor visibility can require a lower speed even when the sign has not changed. Being late or following another vehicle does not create permission to use the maximum. The key cue is maximum, not target speed: evaluate weather, traction, and visibility first, then reduce speed whenever those conditions make the posted number unsafe.

2. 2. Under Louisiana's general speed law, which driving choice is prohibited?

   1. Checking the speedometer often on a clear road
   2. Driving below the posted limit when traffic is light
   3. Driving faster than is reasonable for the conditions
   4. Reducing speed when rain limits visibility
   Show answer

   Driving faster than is reasonable for the conditions. Louisiana's general speed law requires a reasonable speed that matches the area, roadway, traffic, lighting, and weather. A posted limit is not permission to drive that fast in every circumstance. The choice “Driving faster than is reasonable for the conditions” is prohibited because it ignores conditions and can leave the vehicle unable to stop or steer safely. Driving below the limit may be prudent, checking the speedometer helps the driver judge speed, and slowing for rain is specifically a sound response. Use the posted number as an upper boundary, then reduce speed whenever visibility, traction, or traffic makes that necessary.

3. 3. Under Louisiana R.S. 32:61, what maximum applies on an interstate or controlled-access highway unless a different speed zone has been established?

   1. 70 mph
   2. 45 mph
   3. 35 mph
   4. 55 mph
   Show answer

   70 mph. Louisiana's statutory maximum is 70 mph on interstate and controlled-access highways, subject to established speed zones. The ordinary highway baseline is 55 mph, while a multilane divided highway with partial or no access control has a 65 mph maximum. The road classification matters: 70 mph is not the default for every road in the state. Follow the applicable signs and reduce speed whenever traffic, weather, or visibility makes the maximum unsafe.

Source: the Louisiana Class D and E Driver's Guide, Chapter 6: Traffic Laws and Regulations. 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.