Green light, blocked exit: yellow box, bus lane and a cyclist
At 08:10 on a weekday you are driving a 26-tonne rigid lorry, 12.5 m long, on a two-way national road through a suburb with a 50 km/h limit. You intend to turn left at a signal-controlled junction. The left-turn lane is also a bus lane, signed “7.00–10.00 and 16.00–19.00, Mon–Sat”. Your delivery entrance is 30 m along that lane. The signals are green, but beyond the junction the exit road is blocked by a queue of cars that has stopped across the far side of a yellow box junction. A cyclist in the bus lane is 20 m ahead of you. The centre line is continuous on your side until 15 m before the junction, where it becomes broken. A warden is not present and there is no police officer. Your load is 6 t of bottled water and you are running 10 minutes late.
1. The signal is green. May you enter the yellow box junction to begin your left turn? Explain how the markings, the queue and your vehicle length affect the decision.
Read the worked answer
No. A green signal means you may proceed only if the way is clear; it does not give you a right to enter a box junction that you cannot clear.
The yellow box rule is that you must not enter unless you can clear it without stopping. There is a limited exception for a vehicle turning right and prevented only by oncoming traffic, but you are turning left, so that exception does not apply.
Your vehicle is 12.5 m long and the exit road is already blocked by stationary cars. If you enter, your rear overhang or trailer area will stop inside the box and block cross-traffic, possibly including buses and emergency vehicles. Wait at the stop line, even on green, until there is enough space beyond the junction for the whole vehicle. Being 10 minutes late is not a reason to block the junction.
2. May you use the bus lane to reach the entrance, and how should you deal with the cyclist?
Read the worked answer
First check what the bus-lane sign actually permits. Outside the stated hours, the lane is available to general traffic. Inside the hours, it is primarily for buses and other permitted users. A delivery vehicle may normally enter only where access to premises or a side road is allowed, and only for the shortest distance needed - not as a through route and not to overtake a queue.
If access is permitted, signal early and move into the lane only at the entrance. Give way to the cyclist already in the lane: the cyclist is ahead and vulnerable. Do not squeeze past, sound the horn aggressively or cut across the cyclist to reach the entrance. Hold back until the cyclist is clear and you can turn in without forcing them to stop or swerve. If the sign does not permit access, do not use the lane; find a legal alternative approach.
3. What does the broken white line 15 m before the junction allow, and should you use it to overtake the cyclist before turning left?
Read the worked answer
A broken white line permits you to cross the centre line if it is safe and necessary. It removes the absolute prohibition imposed by the continuous line, but it does not create a right to overtake or to ignore other hazards.
You should not use it to overtake the cyclist here. You are approaching a signal-controlled junction, the exit is blocked, and you intend to turn left across the cyclist’s path. Overtaking just before a junction is high risk: the cyclist may continue straight, a vehicle may emerge, and your long vehicle will cut the corner or swing wide. The safe plan is to stay behind the cyclist, signal left, check mirrors and blind spots, and turn only when the cyclist is clear and the exit has space. The broken line changes the line rule, not the judgement.