Speed limits and work zones

Key points

1. The Basic Speed Law means driving at a careful and prudent speed in all conditions.

   Source: Handbook p. 26

   “Michigan’s Basic Speed Law means you must drive at a “careful and prudent” speed in all driving conditions.”
   What Every Driver Must Know, Handbook p. 26

2. Drive at a speed that lets you stop within the clear distance ahead; it is never faster than the posted limit and may be slower.

   Source: Handbook p. 26

   “Drive at a speed that always allows you to stop within the clear distance ahead. This speed is never faster than the posted speed limit.”
   What Every Driver Must Know, Handbook p. 26

3. On a 70 mph freeway, school buses and trucks are limited to 65 mph, and to 55 mph where the freeway limit is lower.

   Source: Handbook p. 26

   “School buses and trucks are restricted to 65 mph. On freeways with speed limits less than 70 mph, school buses and trucks are restricted to 55 mph.”
   What Every Driver Must Know, Handbook p. 26

4. For most construction, maintenance or surveying work, the speed limit is 45 mph unless posted otherwise.

   Source: Handbook p. 27

   “For most construction, maintenance or surveying activities, the speed limit is 45 mph unless posted differently.”
   What Every Driver Must Know, Handbook p. 27

5. Fines are doubled for all moving violations in work zones.

   Source: Handbook p. 27

   “Fines are doubled for all moving violations in work zones.”
   What Every Driver Must Know, Handbook p. 27

6. Speeding in a work zone brings 3 points for 10 mph or less over, 4 points for more than 10 up to 15 over, and 5 points for more than 15 over.

   Source: Handbook p. 27

   “Three points for speeding 10 mph or less over the posted limit. • Four points for speeding more than 10 mph but not more than 15 mph over the limit. • Five points for speeding more than 15 mph over the limit.”
   What Every Driver Must Know, Handbook p. 27

7. Injuring or killing someone in a work zone can bring fines up to $7,500 and up to 15 years in prison.

   Source: Handbook p. 27

   “If you cause the injury or death to any person in a work zone, you may face fines of up to $7,500, and imprisonment of up to 15 years.”
   What Every Driver Must Know, Handbook p. 27

8. Construction workers may direct traffic, and you must follow them even over a traffic control device.

   Source: Handbook p. 27

   “Construction workers also have the authority to direct traffic in work zones and their directions should be followed even if they conflict with an existing traffic control device.”
   What Every Driver Must Know, Handbook p. 27

9. Flashing green lights on a road maintenance vehicle mean slow down and drive with caution.

   Source: Handbook p. 27

   “Motorists should know that when they see flashing green lights on a local or state maintenance vehicle to slow down and drive with caution.”
   What Every Driver Must Know, Handbook p. 27

Numbers to know

Recognize these signs

3 questions from the Michigan practice test

1. 1. Under Michigan's Basic Speed Law, how should a driver choose a speed?

   1. Use a careful and prudent speed for the conditions
   2. Always drive at the posted maximum
   3. Drive exactly 5 mph below the sign
   4. Match the fastest nearby vehicle
   Show answer

   Use a careful and prudent speed for the conditions. Michigan’s Basic Speed Law calls for a careful and prudent speed in all driving conditions. The posted number is a ceiling, not a promise that the same speed is safe in rain, ice, congestion, darkness, or a work area. Matching the fastest nearby vehicle is also not a legal measuring stick. A driver should select a speed that allows stopping within the clear distance ahead and should be ready to reduce it when conditions worsen. The road surface and visibility are the cue to reassess, even when the sign has not changed.

2. 2. For most construction, maintenance, or surveying activities in Michigan, what speed applies unless posted differently?

   1. 25 mph
   2. 45 mph
   3. 55 mph
   4. 70 mph
   Show answer

   45 mph. In Michigan, the listed work-activity speed is 45 mph unless a different limit is posted. The ordinary road limit does not control when this rule applies, and 70 mph is not appropriate simply because the road is wide. A posted variation must still be followed, while the Basic Speed Law may require an even slower speed for traffic, weather, or visibility. Watch for advance work signs, workers, equipment, and changing lane patterns before entering the activity area.

3. 3. What happens to fines for moving violations committed in a Michigan work zone?

   1. They are doubled
   2. They are reduced by half
   3. They stay the same as outside the zone
   4. They are waived for the first offense
   Show answer

   They are doubled. Michigan doubles fines for all moving violations committed in work zones. The increased penalty applies to the moving violation, so it is not waived for a first offense, cut in half, or left unchanged merely because the driver is outside the active lane. Drivers should slow as directed, watch for workers and equipment, and follow the signs and traffic-control instructions around the work area. The cue is the marked construction zone: once inside it, treat ordinary impatience or speeding as carrying an enhanced financial consequence.

Source: the What Every Driver Must Know, Chapter 4: Traffic Laws. 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.