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Controlling traffic light signals at isolated junctions
MOVA
Microprocessor Optimised Vehicle Actuation
The latest versions of MOVA Comm, MOVA Setup and the Application Guides (AG 44 and 45) can be found on the MOVA Downloads page. To keep up with latest MOVA developments, subscribe to the MOVA mailing list below. A MOVA FAQ (Frequently Asked Questions) is also available.
MOVA stands for Microprocessor Optimised Vehicle Actuation. Designed by TRL during the 1980s, it is now a very well established strategy for the control of traffic light signals at isolated junctions – i.e. junctions that are uncoordinated with any neighbouring signals. It can also be used at stand-alone pedestrian crossing, i.e. Puffin and Pelicans. Currently the UK is thought to have at least 3000 sites equipped with MOVA with each year seeing at least another 200 installations. Although designed for isolated junctions, a number of linked schemes have also been installed.
MOVA is designed to cater for the full range of traffic conditions, from very low flows through to a junction that is overloaded. For the major part of the range - before congestion occurs, MOVA operates in a delay minimising mode; if any approach becomes overloaded, the system switches to a capacity maximising procedure. MOVA is also able to operate at a wide range of junctions, from the very simple ‘shuttle-working’, to large, multi-phase multi-lane sites.
MOVA is particularly well suited to the following:
- Sites with high traffic flow, particularly where these are seasonal or intermittent (for instance, motorway diversion routes and holiday routes).
- Sites experiencing capacity difficulties under VA control with congestion on one or more approaches.
- Sites with high speed approaches and/or red compliance problems.
- Where additional capacity is required to allow pedestrian facilities or safer staging structure to be introduced.
- Where more than one junction is situated too close to be considered as isolated, there are ways in which two or more junctions can be linked by the use of MOVA control. Partially or even fully signalised roundabouts are a good example of a MOVA linking opportunity.
- Puffin crossings where the call-cancel demands from kerbside detectors can be dealt with correctly and the identification of gaps in traffic can be considerably more effective than D-system VA.
MOVA is being used by almost all Authorities who have responsibility for traffic signals, and is a requirement on new signal installations and major refurbishments on trunk roads. MOVA can be used in conjunction with any controller conforming to Departmental Specification TR2500 and it is available in one of the following forms:
- Add-on unit that connects to the controller via the standard UTC interface,
- ‘Semi integral’ where MOVA and the Controller are separate but have a dedicated communication link,
- Integral where the MOVA kernel software is incorporated into the Controller (although MOVA still effectively remains a separate component).
For information on specific manufacturer implementations of MOVA and equipment maintenance enquiries, please contact the manufacturers directly:
telent (nee Microsense/TSEU): www.telent.com
Peek: www.peek-traffic.co.uk
Siemens: www.siemens.co.uk/traffic
TRL are able to supply a full range of consultancy services on MOVA. Please contact Mark Crabtree (mcrabtree@trl.co.uk, 01344 770959) for further information.
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