BENEFITS OF MOVA CONTROL AT A PARTIALLY-SIGNALLED ROUNDABOUT

MOVA (Microprocessor Optimised Vehicle Actuation) is the self-optimising control system for traffic signals developed by the Transport Research Laboratory (TRL). It uses an on-line microprocessor to maintain the optimal green stage, cycle time, and control strategy, using prevailing traffic conditions to minimise queuing at signal-controlled junctions. This paper discusses the application of MOVA to partially signalled roundabouts, which are popular in the UK, especially at motorway junctions. MOVA and traditional vehicle-actuated (VA) control strategies are compared. MOVA is proactive and continually optimises green times, so that it handles variable flow rates flexibly. It almost always performs significantly better than the best VA system. The objectives of the installation of the MOVA signal control described here are to: (1) confirm that MOVA can provide well coordinated control of the traffic signals on two adjacent entries to a partially signalled roundabout interchange; (2) improve and integrate into MOVA a special facility to assist the interchange's non-signalled parts; and (3) assess how far MOVA improves VA control. The results for M1 motorway junction 21 with the M69 and A5460, near Leicester, England, are presented, with special reference to better control of gap creation on the priority approach.