Signal offset optimization

Signal offset optimization is used to optimize the offset of signal timing at adjacent nodes, so that vehicles can pass several consecutive signal controllers at green. The general aim is to minimize the total wait time at signal controllers for all vehicles (Fundamentals: Signal coordination (Signal offset optimization))..

Note: Nodes with switched off signal controllers are not included.

1.  Make sure that the input attributes required by this procedure have been set (Fundamentals: Signal coordination (Signal offset optimization)).

2.  From the Calculate menu, choose General procedure settings.

The General procedure settings window opens.

3.  In the navigator, select PrT settings > Signal offset optimization.

4.  Make the desired changes.

Element

Description

Execute analysis after coordination optimization

Select this option to automatically update output link attributes after signal coordination (Fundamentals: Signal coordination (Signal offset optimization)).

Note

This analysis can also be included as a procedure in the procedure sequence (SC offset analysis).

Use coordination group filter

If this option has been selected, the coordination is executed only for the signal controllers of the selected coordination groups.

Use demand segment filter

If this option has been selected, the path legs are determined from the assignment paths of the selected demand segments only. Click the button to select the desired demand segments.

Note

This setting is also used for the signal time-space diagram (Adjusting the signal time-space diagram).

Maximum computation time for optimization

User-defined restriction to the computation time spent for solving the optimization problem. The best solution found up to the specified time limitation, is assigned.

Maximum permitted vol/cap ratio for platooning [%]

If this saturation is exceeded on a path leg link, the path leg is ignored for coordination, because no platoon is retained with too high saturation.

Minimum platoon index

If the platoon index is below this threshold at the end of the path leg, the path leg is ignored for coordination, because the platoon is not distinct enough.

Platoon progression formula according to Robertson

Enter appropriate values for Alpha and Beta required by the platoon progression formula.

Travel times

For each of the network object types, select a numerical attribute for path leg travel time calculation and enter a factor, if applicable.

Note

This setting is also used for the signal time-space diagram (Adjusting the signal time-space diagram).

5.  Add the Signal offset optimization procedure of the Assignments category to the position of your choice in the procedure sequence.

6.  Execute the procedure.

The signal offset optimization is executed.