By iancol -

Riding Skills

 21 January 2009 19:35

Some weeks ago, there was a story about lane discipline on roundabouts - see here

Having checked out available documents I felt that there was an issue to resolve and wrote to Driving Standards Agency (DSA):

I've looked at all the PDF pages of road signs and can't find any examples of the different types of signs for roundabouts, eg showing how lanes leaving a roundabout may be single or dual carriageway. 

Specifically, say I'm entering a roundabout from a dual carriageway and want to go straight ahead.  There are illustrations in the Highway Code for optional routes where the lane I want to join is dual carriageway, but not for the single carriageway exit option. 

I assume that for this, I should approach the roundabout in the left lane but if I don't know the road and assume that the exit lane is dualled, I may stay in the outside lane and then have problems clashing with traffic using the left hand lane.  Specifically, I believe that the sign for the roundabout should show the exit as a single lane, but can't find an illustration to confirm it.

Reply from Driving Standards Agency:

Signs relating to information about the ‘road ahead’ can be found on page 111 and 114 of the Department for Transport publication ‘Know Your Traffic Signs’ (see There may also be advisory road markings present (page 63). As you will appreciate it is not possible for us to comment on a hypothetical situation other than to refer you to rules 184 to 190 of the Highway Code with regards the use of roundabouts. Advice on roundabout procedure is also provided in the DSA publication, ‘Driving  - the essential skills’.

Further Request to DSA:

I have now had time to look at the reference you gave me and feel that there's a gap in the paperwork.  The text on page 95 of the "Know your traffic signs" PDF shows a roundabout below the text:

"The width of each route symbol depends on the type of the road indicated: wide for primary routes and motorways, medium for "A" and "B" numbered non-primary routes and narrow for local roads without numbers." 

This is deficient in not covering two-lane road joining/leaving the roundabout. The Highway Code (at least my copy) covers lane positioning on two lane in/out junctions, but not the case where there may be two lanes joining but one lane going out in the straight ahead direction.  This may sound picky but the query I have arose out of a report by a motorcyclist who took such a junction and was almost involved in a accident.

The Highway Code should be modified to reflect this sort of situation, ie single lane roundabout exits after a multi-lane entry; 2.   Examples of roundabout signs should show two-lane road details as well as designating importance by line width. Please consider and advise.

Further Reply from DSA:

The Highway Code is written in general terms and cannot cover every scenario that may occur on the road. As my colleague Mr Armstrong said in his previous letter we can not give a definitive answer on any hypothetical situation. There are far too many variables that would influence a driver or rider’s decision, such as road markings and the position of other traffic. We can only highlight the rules and guidance that all drivers and riders should be aware of when using the road. When you are approaching a roundabout you should always look well ahead for the advance warning sign. This sign will enable you to select the most suitable lane to use. Looking at your diagram the left lane would seem the obvious choice in most instances. ‘The official DSA guide to driving – the essential skills’ gives the following advice on lane selection when going ahead at roundabouts – ‘Approach in the left hand lane. If you can’t use the left hand lane because, for example, it’s blocked, use the next lane to it.’ The choice of lane would not usually be dependent on whether the exit road is single or dual lane unless, of course, road signs or markings indicate otherwise. You should not accelerate when someone is overtaking you. You should ease off if necessary to help them pass. I will forward you email to our Publications Department who hold any suggestions on Highway Code content. They will review this when the next update is due. I hope this helps to clarify the situation.

I replied that I still think that the Highway Code could be amended to show the route for leaving a dual carriageway and entering a single track road.