Overtaking a cyclist before a blind crest on the RN1
You are driving a light truck southbound on a two-lane rural road. It is 17:40, the light is fading but visibility is still about 150 m. Ahead of you a cyclist is riding at roughly 15 km/h about 40 cm from the right-hand edge, weaving slightly. Your speed is 70 km/h. The road climbs to a blind crest about 90 m ahead, and the centre line is a single broken white line. You have 12 tonnes of loaded cargo and the truck is not fully loaded evenly - the rear sits low. An oncoming car passed you about 20 seconds ago; no other traffic is currently visible. Your stopping distance at this speed on dry tarmac is roughly 55–60 m, and the crest hides anything beyond it.
1. Should you overtake the cyclist before the crest? Justify your decision using the geometry and the vehicle's state.
Read the worked answer
No. Work through the numbers:
- Space to the crest: ~90 m. To overtake safely you must be back in your lane and clear of the cyclist before the crest, because beyond it you cannot see oncoming traffic.
- Speed differential: you are doing ~70 km/h (≈19.4 m/s) and the cyclist ~15 km/h (≈4.2 m/s), so you close at ~15 m/s. Even a short pass needs a lateral offset plus a safe return gap - realistically 60–80 m of clear road, which leaves almost nothing before the blind point.
- Stopping distance: 55–60 m at 70 km/h. If an oncoming vehicle or a stopped obstacle appears just over the crest, you would need most of your remaining sight distance simply to stop.
- Load: the rear-heavy, low-sitting truck lengthens braking and makes the steering response sluggish; the effective stopping distance is worse than the dry-road figure.
- Cyclist behaviour: the cyclist is weaving 40 cm from the edge, so you cannot assume a predictable straight line - you need extra lateral clearance.
Correct action: hold back, reduce speed to widen your safety margin, keep well left of the cyclist's line, and wait until you are over the crest with a clear view and a confirmed empty oncoming lane before passing with a wide berth.
2. What following distance and lane position should you adopt while waiting behind the cyclist, and why?
Read the worked answer
Lane position: stay in your lane but position the truck slightly toward the centre of the road only when it is safe and legal - the aim is to be visible in the cyclist's peripheral vision and to discourage the cyclist from drifting further into your path, without crossing into the oncoming lane on a blind crest.
Following distance: keep at least 2–3 seconds behind at minimum, but because of the crest, the heavy uneven load and the cyclist's weaving, extend this. A practical rule: you should be able to stop well short of the cyclist even if they fall. At 70 km/h that means a gap of roughly 40–50 m, not the bare 2-second (~39 m) minimum.
Why: a loaded truck cannot swerve sharply, and a cyclist who wobbles or falls gives you almost no reaction time. A generous gap converts a potential emergency stop into a controlled slowdown and keeps you out of the oncoming lane on a blind approach.