Frequently asked questions: Traffic management and road safety

Traffic management and road safety questions

• Question: Why are alterations made to the highway when there does not seem to be a problem?

• Question: Why are traffic signals installed?

• Question: Why do I sit waiting at a red signal when there are no opposing vehicles?

  Answer:

  It is our intention to use modes of operation such as MOVA, SCOOT and VA which are responsive to live traffic flows. These modes respond to vehicles approaching signals and provide a green signal to the necessary approach.

  At different times of day or at sites that are not yet capable of running the modes of operation mentioned above the signals may run ‘fixed time plans' which is useful to operate on a number of closely situated junctions so that they can be be co-ordinated. This would usually run at peak times at sites when flows are predictable.

  Alternatively, there may be a vehicle detector fault on the other approach causing it to call an approach unnecessarily and ‘extend’ the green time. This will be more noticeable at night or during the early hours of the morning.
  

• Question: I have seen traffic signals with right turn arrows that never seem to appear. Why is this?

• Question: At pedestrian crossings why does the ‘green man’ time seem so short?