CYCLE LAWS AT ROAD JUNCTIONS: British road rules 72 to 75 explain how cyclists should use intersections.
Highway Code Junction on the Left Side
Rule 72: Cyclists approaching a junction on the left should watch out for vehicles turning across or in front of them. Traffic can also come out of, or into, the side road.
Make a final check immediately before turning into a road junction. There may be ‘undertaking cyclists or motorcyclists‘ moving on the inside.
Never ride on the inside of vehicles which are signalling or slowing down in preparation of making a left turn.
Cyclists and Long Vehicles
Rule 73: As a cyclist, you should pay particular attention to a long vehicle. They will need a lot of room for their maneuvers at the corners of an intersection. Be aware that drivers of long vehicles may not see you.
Note: Long vehicles may have to move over slightly to the right before making a left turn into the junction.
Cycle riders should wait until large vehicles have completed their maneuver. The rear wheels of a truck often come very close to the kerbside when they make a turn.
Avoid riding your bicycle in the space between the long vehicle and the kerb.
Be sure to check the rules for cyclists using roundabouts and other types of road circles.
Highway Code Junctions: Right Side
Rule 74: Cyclists who are turning right into a junction should check the traffic to ensure it is safe. Then, give a signal and move to the center of the road.
Be sure to wait until there is a safe gap in the oncoming traffic. Give a final look before completing the right turn across the road and into the intersection.
As a rule it may be safer for cyclists to wait on the left until there is a safe gap. In some cases it is better to dismount and push your cycle across the road.
Cyclists Crossing Dual Carriageways
Rule 75: The Highway Code for cyclists places extra caution in the rules for cycling on dual carriageways. Cycle riders should remember that traffic moves at speed on most dual carriageways in the United Kingdom.
That means you should cross only when there is a safe gap and cross each carriageway in turn. Cyclists who are crossing the road and slip roads should take extra care and use due diligence.