The Critical Speed Application allows the investigator to determine the critical speed of a vehicle that has entered a yawl. The speed calculations are based on the radius that is derived from the chord and middle ordinate obtained from one of the vehicle’s yawl marks, in conjunction with the drag factor and super elevation of the roadway. The application also adjusts the radius for the track width of the vehicle if so desired.

Calculations may be performed using the Imperial or Metric system. In the Imperial System the speed calculations will be displayed in both fps and mph. In the Metric System the results will be displayed in m/s and km/h.

The chord of the applicable yawl is entered into the program through the use of a text box. All other data, Middle Ordinate, Drag Factor, Super Elevation and Vehicle Track Width are entered via sliders. When any of the sliders are changed their related values change as well as all of the related calculations. This allows the user to determine the sensitivity of their data by simply moving the sliders, eliminating the need to constantly reenter data.