PROMPT (Priority and Informatics in Public Transport) was a collaborative study funded within the European Commissions DRIVEII programme into applications of Advanced Transport Telematics (ATT). PROMPT was concerned with the development, implementation and evaluation of active public transport priority in modern traffic responsive Urban Traffic Control systems. The project involved developments and field trials in the three cities in London, Turin and Gothenburg, each city having experience in, and commitment to, advanced traffic control systems and public transport priority at traffic signals. An application of PROMPT in Southampton was also undertaken and is described briefly. This paper is concerned with the results of the simulation and field trial activities in PROMPT related to bus priority in SCOOT.