Signal Controlled Roundabouts - a New Guidance Paper

Signal Controlled Roundabouts - a New Guidance Paper


C Ridding, Mott MacDonald, UK; S Phull, Department for Transport, UK



Local Transport Note 1/09 ?Signal Controlled Roundabouts? is due for release in mid-2009. This much needed and long awaited document will provide comprehensive guidance to those engaged in the design of signalised roundabouts. These include existing roundabouts to which signals are being added and new junctions conceived as signalised roundabouts from the outset.

The optimum design and control of signalised roundabouts has become a specialised area requiring more detailed analysis and assessment than a conventional signalised junction. This LTN is aimed at experienced traffic control engineers to enable them to identify the issues that need to be addressed and provide them with guidance on how they can be dealt with.

The LTN provides advice on

? Initial assessments
? Partial and full signalisation
? Part-time and full-time signalling
? Traffic modelling techniques
? The choice and use of modelling software
? Control strategies
? Road marking
? Signing
? Catering for pedestrians and cyclists

The document was developed as part of a larger project awarded to Mott MacDonald by the Department for Transport. This included a review of UK current practice, identification of factors affecting the safety, efficiency and capacity of signalised roundabouts and conducting a modelling and validating exercise to determine the key variables in the decision to use signals at a roundabout.

The draft document was refined by an extensive consultation exercise involving special interest groups (pedestrians, cyclists, disabled road users) as well as all the key practitioners in the traffic control field. It is hoped that this document will for the first time provide users with a clear and practical guide to assist with the assessment, design and implementation of signalised roundabouts.


Association for European Transport