Skid mark speed
Estimate minimum speed from tire-mark distance, drag factor, grade, and braking efficiency.
View the skid speed guideField worksheets for investigators
Traffic Crash Investigation Tools
Run transparent, field-ready calculations for tire marks, yaw, momentum, crush, delta-V, scene conditions, and case reporting. Every formula shows the inputs, equation, and worked arithmetic.
60+investigation worksheets
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Start with the evidence you have
Use a focused guide to understand the method, inputs, limitations, and source material before opening the live worksheet.
Critical speed yaw
Calculate critical speed from a curved tire mark's radius and surface drag factor.
View the yaw speed guideCollision momentum
Work through one- and two-dimensional conservation of momentum calculations.
View the momentum guideCrush energy
Estimate absorbed energy from a measured damage profile and stiffness coefficients.
View the crush energy guideDelta-V
Relate crush energy and vehicle mass to velocity change with stated assumptions.
View the delta-V guidePedestrian throw
Apply the Searle method and report a defensible speed range instead of a single value.
View the pedestrian throw guideEvidence-first discovery
Not sure which worksheet fits?
Start with the evidence documented in the case—straight or curved tire marks, final rest, damage, video, EDR/CDR, throw, sight distance, or wet-road conditions.
Transparent by design
Numbers that can be checked
Enter measured evidence
Record distances, weights, drag factors, angles, and other case-specific inputs.
Review the worked solution
See the equation, unit conversions, substituted values, and arithmetic behind the result.
Export the record
Save worksheets with notes and limitations for review, reporting, or court exhibits.
Built for professional judgment—not a substitute for it
CrashCompute implements published calculation methods. Results depend on the quality of the measurements and assumptions entered and should be corroborated with the physical evidence and an independent method.