Software quality -- the Midas touch

Modern transport systems contain an ever increasing proportion of software. A good example of this is the MIDAS system of the UK Department of Transport (DoT). Using inductive loops fitted in each lane, MIDAS will monitor traffic flow on motorways, detecting the formation of queues and slow-moving traffic. It will then automatically set motorway signals and newly styled message signs to give speed restrictions, warnings or alternative route information. The MIDAS system is an evolution of earlier automatic incident detection and automatic traffic surveillance systems tested by the DoT, which were already quite sophisticated. In the case of the MIDAS system there may be typically 50 to 100 software-controlled data processing out-stations (one per set of loops) which feed data ultimately to each central Control Office. This paper outlines the measures adopted by the company that designed the MIDAS system to ensure software quality.