What do you do when control plan data is not available? You might face this problem when working with future scenarios that have not been fully detailed, or on a first approach from macroscopic to dynamic. In dynamic simulations, you can manage simple intersections with vertical signs for priority (give way and stop signs), but for more complex intersections that should be regulated with traffic lights, you cannot omit this information.

Aimsun Next offers a functionality that will estimate a reasonable control plan (fixed or actuated) for a single node or set of nodes, based on the volumes in the approaches and turns – a piece of information that you can input manually from field observations or extract automatically from a macroscopic assignment. Note that when calculating the control plan for several nodes, the offset is not calculated automatically, so after the plans have been computed, you’ll need to make manual adjustments to ensure coordination along a corridor.

When you select an existing control plan in “Use Control Plan”, the calculation procedure will not alter the association of signal groups to phases and the sequence of the phases. This is useful when you want to adapt the real control plan of the base scenario to the change of demand in a future scenario. Note that the procedure overwrites the selected control plan, so you should first make a copy of the base control plan and select that copy when you run the calculation.

When you select “Generate New Control Plan”in “Use Control Plan”, if signal groups are already defined in a node, they will be used, whereas if the node doesn’t contain any signal groups, they will be automatically created based on a logic that groups non conflicting turns in the same phase, and then splits the movements of each phase into a signal group per approach.