How to optimise network offsets wile retaining specific green times

Question: What if I wish to optimise the node offsets of a network, but do not wish to change some specific green times?

Answer: In TRANSYT 16 and TRANSYT 15, under “Controller Stream N > Optimisation (OFF/ON)” you can simply deselect the box “Allow Green Split Optimisation”. This will ensure that the green times on Controller Stream N will not change.

In TRANSYT 14, under “Network Options > Optimisation Options” you can add the controller stream ID to a comma-separated list of “Locked Green Splits”. This will ensure that the green times on the controller streams listed will not change.

In TRANSYT 13 it not quite so easy to lock green splits, but you can still manage it relatively easily. If you specify your previously-established green times as “User Stage Minimums” for each stage of the node, this along with your intergreens, will define the whole of the cycle (which you have to enter). As a result the TRANSYT optimiser will no longer be able to adjust green times and can only adjust the offset.