Compared to the middle of their shifts, commercial drivers are 26% more likely to exhibit
unsafe driving than at the start and 41% at the end of their shift. This was measured by four metrics:
- Harsh Acceleration
- Harsh Braking
- Distracted Driving
- Tailgating
Since Jan. 1, 2020, 2 million such events were detected in U.S. commercial fleets. Shift lengths ranged from four to 12 hours, but these unsafe trends appeared consistent throughout.

One statistic that jumps out is harsh acceleration. Harsh acceleration occurs 77% more often during the end of the shift than in the middle. That’s nearly double the frequency at the beginning of a shift relative to the middle (39%). Harsh braking has similar results, with 54% more likely at the end versus 28% at the beginning.
Conversely, distracted driving is 36% more likely during the first part of the shift, which is twice as much as at the middle-to-end difference.