Question: I want to call up a pedestrian cycle in alternative stages. I am not sure how to input this into the model.

Answer:  You have either one or two options how to do this, depending on the version of TRANSYT you are using, and is relatively easy to set up.

(1) The first option, which is available in all versions of TRANSYT is this, and here are the steps involved if using TRANSYT 16:

  1. Double-click on the controller in the Network Diagram – That will bring up the Controller Streams data screen
  2. Select the “Stage Sequences” tab, and change “Multi-cycling” to “Double”
  3. Open the Phase “Timings Diagram” (if not already open) – There is a shortcut (button) on the Controller Streams data screen to do that
  4. Press the “repair timings” button to repair the stage timings
  5. Select Tools > “Convert all stages to base stages”. This means you now have every stage running twice within the cycle – N.B. you may need/want to double the cycle time at this stage. The need to convert the stages to “base stages” is to allow you to remove one of the stages which runs your pedestrian phase.
  6. (N.B. The following assumes you have at least 3 stages)
  7. In the Timings Diagram, right-click on the first or second stage that is running your pedestrian phase, and select “Remove Stage”.
  8. Press the “repair timings” button again, to repair the stage timings

You now have your pedestrian phase running every second cycle in effect – technically you have all but the stage containing the pedestrian phase, running twice in one cycle.

Through the use of triple or quadruple cycling, you can choose to model a pedestrian stage that comes in every second, third or fourth cycle, in effect.

N.B. alternatively, you can create the required new stages manually using the data outline and data editor, and then change the stage sequence that TRANSYT is currently using. Both methods result in the same file data, but it will often be quicker to do it in the way set out above.

(2) The second option, which is only available in TRANSYT 16, makes use of a relatively new facility provided through the use of TRANSYT’s “Simulation Model”.  Please note that in Simulation signal timings cannot be optimised.

  1. Switch your model into Simulation, by clicking the “Simulation” button on the left-hand vertical toolbar
  2. Navigate via the Data Outline to the “Library Stage” that is your pedestrian stage
  3. Click “Allow intermittent occurrence”
  4. For the stage, you now have the option of getting it to “Run every N cycles” or entering a “Probability of running”.
  5. We do not recommend selecting both, so either leave “Run every N cycles” = 1, or “Probability of running” = 100%
  6. By changing one of these parameters you can control what happens – either your pedestrian stage will run regularly every N cycles, or it will run randomly (i.e. be skipped sometimes) such that on average it will run in X percent of the cycles

This second offer offers, at the expense of not being able to optimise timings, a more accurate portrayal of your pedestrian crossing, and hence give better results.

(Article updated – June 2023)