Hi,

I am trying to figure out if my logic is correct when picking the right control type for an intersection based ONLY on the timing sheets information.

My understanding is that if an intersection is belonging to a coordination system, it needs to have some kind of offset information be provided, for the most of the case, unless it is a master. Now the next step is to identify if it is Pre-Timed or Actuated-Coordinated. If it is Actuated-Coordinated, then Vehicle Extension field in the Timing Sheets needs to have something value other than zero since the controller needs to have this information to end a phase. If this value is zero, then it is safely to select it as a Pre-Time.

Let me know if you have any thought/comment on this.

Thanks,

mtran

Keep in mind that the zero point for offsets is completely arbitrary. Any local could be the zero point, and the controller in the cabinet with the on-street master could have a numerical offset.

There may be no data in the vehicle extension field. Many controllers have multiple layers of detection settings. You can have for instance in the timing sheet a "min gap", and a "vehicle extension". The min gap can be any value, including zero. In general, the min gap assumes that you are using gap reduction. The vehicle extension assumes that each actuation on that specific phase would extend the green by the value.

Additionally, in detection settings in the controller, there are other detector channel by detector channel settings for delay and extension.

Additionally, the deteciton amplifiers typically include the ability to extend and delay inside the detection channel on the amplifier. So the signal could be set up to have 0's in all of the controller settings for gap, phase extension, and detection extensions, and all of the extension timing within the detectors.