Amber Light, Box Junction and a Cyclist in the Bus Lane
You are driving a 12.2 m single-deck bus carrying 47 passengers in light rain on a two-lane urban road with a 50 km/h limit. You are 18 m from a signal-controlled junction when the light turns amber. Your speed is 40 km/h. Beyond the stop line is a yellow box junction; the exit road is occupied by a queue of cars that would leave about 12 m of the box clear. A cyclist in dark clothing is travelling ahead of you in the bus lane at about 20 km/h, and the bus lane ends 30 m after the junction. A car behind is close and sounding its horn. The road surface is wet, and your bus has a laden braking distance longer than a car's. You must decide whether to stop or continue, how to treat the box junction, and how to pass the cyclist without trapping them.
1. What should you do as the amber light appears, and why?
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Amber means stop at the stop line unless stopping would be unsafe. At 40 km/h you are covering about 11 m each second, and 18 m is not enough for a laden bus on a wet road to stop smoothly: reaction distance alone is about 11 m, leaving too little for braking. Braking hard would also risk passengers falling. So continue through the amber only after checking the mirror and the junction, keeping speed low and being ready to stop before the yellow box if the exit is blocked. Do not accelerate to beat the red. If you can stop safely in time, you must stop; the decision turns on the wet, laden stopping distance, not on the horn behind.
2. The exit beyond the junction is blocked. How does the yellow box rule affect your decision?
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A yellow box junction may only be entered when you can clear it without stopping. A 12.2 m bus needs the whole box and the exit to be free; a 12 m gap is not enough because the queue can stop again. If the amber decision has already taken you across the stop line, stop at the box entrance, not inside it, and wait until the exit is clear. Do not follow the car ahead into the box: that is how buses block cross traffic, pedestrians and emergency vehicles, and it is an offence. The safe plan is to hold back before the yellow lines, even if the light is green or amber, until there is space on the far side.
3. How should you pass the cyclist as the bus lane ends?
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Treat the cyclist as a vulnerable road user and expect them to move out as the lane ends. At 40-50 km/h, leave at least 1 m when passing, and more if the cyclist is unstable in the rain. Do not overtake into the narrow section; hang back, check the right mirror and blind spot, signal, and merge behind rather than squeezing past. The cyclist may need to take the centre of the lane to avoid drains or the wet edge. Passing close would risk a fall and a collision, and the bus cannot stop quickly with 47 passengers. If there is not enough clear road, wait.