Time, distance & velocity
Total Stopping Distance Calculator
Combine distance traveled during perception and reaction with the distance required to brake to a stop.
Method overview
The worksheet keeps the response interval and physical braking phase separate. That makes it easier to identify which inputs came from evidence and which depend on an analytical assumption.
Evidence to document
- Vehicle speed at the start of the interval.
- A supported perception-reaction time.
- Measured or otherwise supported drag factor.
- Roadway grade and braking-efficiency conditions.
Limitations
A stopping-distance result does not establish when a driver actually perceived a hazard. The available cue and the selected response time require independent support.
Record measurements, assumptions, units, rounding, and source material so another investigator can reproduce the result. See the methodology and validation center for verification policy and citation guidance.
Related tools
Perception-reaction distance · Skid mark speed · Open AASHTO sight distance