AutoGreen technology

What is AutoGreen® Technology?

AutoGreen® is an advanced form of radar based Vehicle Actuation (VA) for Hollco portable traffic signals.

For a standard 2-phase system on a 50m length of roadworks AutoGreen® can improve traffic flow in cars per hour by up to 24% compared to traditional VA based systems based on ‘Pink Book’ recommendations. This can reduce driver frustration and remove the need for Manual Control on those sites where traffic density is suitable for AutoGreen® control.

Traditional VA systems for portable signals use simple Doppler radars as the detection input for the signals. Owing to the lack of high quality detection data, these detectors give rise to a host of known inefficiencies in the system and hence whilst providing an effective VA system 
it is one that is less than optimised.

The radars used on the AutoGreen® system are specially designed, low-power, FMCW radars which are capable of separately tracking each approaching vehicle with their associated range and speed. This data rich detection can be used to reduce false detection rates, increase detection reliability and further optimise the Green signal timings 
for better traffic flow.

What are the Benefits of AutoGreen®

Some of the functional differences to be seen by the user of a system running AutoGreen®:

  • Complete weather invariability
  • No false alarms owing to driving rain
  • Correct operation under or near high tension power lines
  • Invariability of detection range owing to target type (traditional Doppler radars can have possibly 90m for an HGV)
  • Closing of a Green phase faster after the last vehicle has passed
  • Closing of a Green phase much faster if only a few cars have made a phase call
  • When a queue begins to lengthen on one end the max Green time will be extended to help clear the queue
  • The max Green time will continue to be increased (up to a pre-set max) should the queue not be readily cleared
  • The Green phases will dynamically adjust allowing for ‘tidal flow’ conditions at different parts of the day.
  • Near elimination of Green extension ‘gap out’ inefficiencies
  • The optimum phase rotation based on 35m platoon gaps

Future Developments

This initial, 2-phase only, implementation of AutoGreen® is a first step of improving traffic control at portable traffic installations. A second wave of AutoGreen® functions are currently under development to optimally handle the most congested sites as well as introducing new safety features using the available radar data to make next generation intelligent portable systems.