Hundreds of low headroom locations throughout the world now benefit from the installation of Coeval overheight vehicle detectors. The infra-red based system, coupled with high intensity “secret” signing offer great reliability in detecting and warning drivers of high vehicles to “DIVERT or TURN BACK”

Type approved to UK Highways Agency specifications, the post mounted twin infra-red beams are normally set at the same height as the height restriction some distance farther down the road. The overheight vehicle harmlessly breaks the infra-red beams, causing the high intensity secret sign to illuminate for a short period of time. The driver then is fully aware that they are too high to pass under the obstacle ahead and takes the action to divert or turn back as the sign instructs.

Inductive loops installed in the carriageway beneath the infra-red beams can also form part of the detection logic. The loop proves that a vehicle is actually present when the beams are broken.

Several lanes of traffic can be covered as the detectors can span up to 50 metres.