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Headway vs Gap

Separation is the time in front of a vehicle to the last vehicle travelling in the same direction. The Separation page in the Advanced Profile options provides the option to define separation as:

  • Headway - time between the first axles of two vehicles.

  • Gap - time between the last axle and first axle of two vehicles.

    Separation definitions

    Separation definitions

When using gap, the Estimate vehicle overhang option makes a reasonable adjustment to the actual value to account for the distance between the detected axle and the physical end of the vehicle.

Separation definition

Separation definition

Separation Bins

Editing Separation Bins

Separation bins, like speed bins, are user-definable up to a maximum of 30 bins. The separation unit is seconds, and uses the separation definition option described above.

The list of separation bins is contiguous. Each separation bin includes its lower bound, but not its upper bound. For example, the bin 1-2 includes all vehicles with a separation of one second and above, but less than two.

Separation bins are added by entering a value in the Breakpoint box, and clicking the Add bin button. This will split the bin that contains the entered value, creating two new bins. For example, given the bin 0-0.5 adding a bin at 0.25 will result in the bins 0-0.25 and 0.25-0.5.

Selecting a bin and clicking the Delete bin button will remove the bin, and join the upper bound of the preceding bin to the lower bound of the following bin. For example, given the bins 1-2,2-4 and 4-8, deleting 2-4 will leave 1-4 and 4-8.

The Default button at the bottom will return the separation bins to a typical set of values.

Separation Bin Multipliers

Each separation bin has a user-defined weighting value called a Multiplier. Multiplying the total vehicles in each separation bin by the bin's multiplier, and summing the results gives a value called the Separation Rating.

Changing a bin's multiplier is simply a matter of selecting the bin, and entering a number in the Bin multiplier box. The bin's multiplier will automatically update.