This article outlines the history of pedestrian crossings in the UK, and describes the pedestrian and vehicle detection equipment for them developed by AGD Systems Ltd. The zebra crossing worked well for many years, especially for relatively low road densities. Then the Pelican crossing, incorporating vehicle detection, was introduced. After that, the Puffin (Pedestrian Friendly Intelligent Crossing) also included systems to detect pedestrians waiting to cross the road. The Toucan crossing, now being developed, has a similar principle, but also contains features designed to apply to cyclists especially. In the Puffin, the pedestrian first presses a button to ask to cross the road. A minimum vehicle precedence period can allow other pedestrians to enter the crossing area. Pedestrians are detected there, either by above ground sensors like the AGD420 or by 'mats', in-ground sensors such as those made by Traffic 2000. The AGD sensor can monitor a pedestrian area 2.8m along the pedestrian pavement by 1.6m wide. If a pedestrian leaves the wait area, the request to cross may be cancelled. The AGD220 Pedestrian On-Crossing Detector is usually used in pairs to monitor a crossing from both ends. Approaching vehicles can be detected by above-ground radar vehicle detectors like the AGD2000 or by induction loops.
Samenvatting