Forward calculation


Definition / notice:
The use of the terms initial and terminal speed relates to the position within the calculation and the calculation direction in this calculation dialog. In the scope of a forward calculation, if you carry out an avoidability analysis, for example, taking the permitted maximum speed, then the selected permitted maximum speed is the initial speed in the calculation dialog. If you calculate through to when the vehicle stops, then the final speed in this example is '0'.

The driving and movement lines in the distance-time diagram are calculated in intervals and displayed graphically in the scope of a reverse calculation.

In the first movement section, 6 intervals are offered, this certainly being sufficient for a variety of calculations without impairing the clarity. In the case of more complex sequences of accidents events, you can freely define further calculation intervals by attaching further calculation intervals to the respective last calculated position and the current speed there.

The input in the respective interval concerned takes place row by row and from left to right, beginning in the top left hand corner of the calculation table. As soon as you have entered 3 of 5 values in the first input line, the missing values ware calculated and displayed. If you have made a typing error, your attention will be drawn to more or less meaningful suggestions.

This is how the calculation dialog looks for the forward calculation:


The function and meaning of the individual boxes and elements are explained under Reverse calculation.


The example above examines in the scope of an avoidability analysis whether the example of the presented accident under Reverse calculation could have been avoided when adhering to the permitted maximum speed. In that case, the initial speed was determined as 40 mph. With the data given above, for the permitted maximum speed of 30 mph the result is a braking distance of just under 77 ft. The actual path from the reaction of the driver to the collision was about 118 ft as calculated here. The accident could thus have been avoided when adhering to the permitted maximum speed of 30 mph. The vehicle would have come to a standstill 118ft-77ft = 41 ft ahead of the actual collision point.

In the distance-time diagram, it then looks like this: