Samenvatting
The author outlines the development of portable traffic signals, from mechanical vehicle actuated systems to microwave detection and the lux detector. Details are given of the national portable traffic signals trials, Somerset county trials and the Hullavington field trials which highlighted the capabilities and limitations of the equipment. As a result of the tests, the road cross cable protection was improved and the minimum green recall was perfected. For the covering abstract of the seminar see IRRD 273510.