Manual Tracking

Manually define the path along which a vehicle must travel.

A tracking path is the path that is used in simulating vehicle movement. This path can be defined by drawing lines and arcs in CAD. There are, however, a couple of guidelines to be followed in doing this:

• The tracking path must start and end with a straight line.

• When reverse simulation around a curve has to be done, a straight line must follow each curve.

• The path can be drawn in any CAD layer, but it makes sense to draw it in a separate layer.

Procedure

1. You are prompted to:

TURN: Select the road centreline one element at a time (right-click to finish)

2. indicate each line or arc in sequence of vehicle movement. As you define the path the elements are highlighted to enable you to verify the result. 

3. Right-click to indicate the end of the path.

4. The program calculates coordinates according to the Coordination Interval value specified in the Setup, along the specified path.  These coordinates are kept in memory until you run the Define Path function again.

Remember that it is impossible for a driver to follow a predefined tracking path along a real roadway exactly.  Therefore, the results must be used rather conservatively, and extra allowance beyond the generated envelopes must be made for driver variation, according to sound engineering discretion.