There are several conflicting road rules for cyclists using roundabouts. But, in most cases staying away from the edge is the safest way to cycle around a roundabout.
CYCLE LAWS ROUNDABOUTS: UK Highway Code rules cover regulations for riding a bike round a roundabout in the United Kingdom.
Rule 76: There are further details on safe roundabout procedures in the 'using the road' section.
Traffic circles can be a hazardous area to follow the bicycle roundabout rules. So, cycling rules at roundabouts requires a cautious approach.
Rule 77: As a rule cyclists may feel safer getting off the bike and walking it around on the pavement or the nearby verge. If you decide to ride around the traffic circle keeping to the left-hand lane, you should:
Note: Not all cyclists feel comfortable negotiating all roundabouts. Two-lane and multi-lane gyratory systems can be intimidating. Consider dismounting the bike on the approach to the circle. You can then negotiate a dangerous roundabout the same way as pedestrians do.
Rule 78: Bicycle riders should give plenty of room to long vehicles moving through a traffic circle. Big trucks will need more space to maneuver.
Cyclists should avoid riding in the space large vehicles need to get around. In some cases, it may be safer to wait. Let them clear the roundabout before you cycle around the roundabout.
Choose the appropriate traffic lane as you signal your approach and enter the roundabout. Cycle in the center of the traffic lane for your direction. This is how cyclists should use roundabouts even if it is a single entrance lane.
This should prevent drivers speeding up around and in front of you to the entrance. It also helps prevent drivers from cutting across you to exit left off the circle.
Pedal in a gear that allows you to speed up where necessary. Remember to give clear signals to the drivers behind you before you exit left or right.
Riders of pedal cycles should give way to traffic on the circle and only join when it if safe to do so. Be assertive as you take your lane to dissuade other motorists from cutting across you. Make a signal left as you approach your exit and leave the roundabout.
Always give way to traffic already on the circle and do not join until it is safe to do so. Most cyclists will use the outer lane on a two-lane roundabout (closest to the center circle). But, that option may change according to multi lane roundabout rules.
Make a signal left after passing the exit immediately before the one you want to take. Always check over your left shoulder for other traffic before peeling off left. Be assertive as you ride off and avoid making sudden changes of direction. As a rule, take the left-most lane when going straight ahead.
Tips for Assertive Cycling: Bicycles are a part of vehicle traffic in the same way as cars and trucks. Be positive as you ride and other motorists will react accordingly. Always let other drivers know where you are heading and what you want to do.
Extra care is always needed at roundabouts after or during rainy weather. Wet roads turn spilled dry diesel into slick and slippery conditions. Cycling in adverse weather conditions will make turning, cornering, and braking more difficult.
Cyclists Highway Code Roundabouts in the United Kingdom