Three Cyclists on the Causeway
On a bright June evening you are driving a compact car eastbound on a two-lane causeway that links a coastal town to the mainland. The posted limit is 80 km/h. You are doing 75 with a loaded log truck close behind. Ahead, three cyclists on a club ride are travelling the same direction, riding two abreast and occupying most of the right-hand lane; the paved shoulder is about 40 cm wide and drops off to a guardrail, and the centre line is solid. A line of oncoming traffic - at least four vehicles, the first a pickup towing a boat - is visible about 200 m ahead and closing. The sun is low behind you, directly in the oncoming drivers' eyes, and there is no place to pull off for 1.5 km. The cyclists are holding a steady line, but the road surface at the causeway joints is uneven.
1. What must be true before you begin a pass here, and how much clearance do you aim to leave?
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Before the wheels cross the centre line you need three things: the oncoming lane clear for the whole manoeuvre, not just the first fifty metres; enough sight distance to finish the pass even if the cyclists accelerate - at a closing speed of roughly 150 km/h against that oncoming line, you need several hundred metres of clear view; and legal permission to cross, because a solid centre line prohibits it whatever the gap. Aim for at least one metre of clearance and closer to 1.5 m at 75-80 km/h, since a cyclist's line wanders at the uneven causeway joints and a wobble at the wrong moment is the whole risk. Two of the three conditions fail here: the oncoming traffic is closing at 200 m and the line is solid. You wait.
2. The log truck behind is pressuring you. How do you manage that without taking a bad gap?
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The truck does not own your braking point. A loaded log truck cannot stop in the distance you can, but that is an argument for it keeping its own following distance - not for you to enter a gap you would not otherwise take. Hold your speed steady, brake progressively so you are predictable, and use the brake lights early to broadcast that the cyclists are slowing you. Do not brake-check. If the pressure genuinely feels unsafe, reduce your own exposure rather than gambling: slow, signal, and take the next pull-off to let the truck go by. Being tailgated raises the cost of a mistake; it never lowers the standard for the pass, and a driver who passes to satisfy someone behind them has handed their judgement to a stranger.
3. How does the low sun behind you change the decision, and what do you do if a pass is already under way and an oncoming vehicle appears?
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Low sun behind you means the oncoming drivers' eyes are not adapted to you, and their windshields are probably streaked with dust and insect film. A driver who cannot see you will not leave you room to abort, so assume the oncoming traffic may not brake or hold its lane. That raises the required gap rather than lowering it: if you cannot confirm the oncoming drivers have registered you, do not start the pass. If one is already under way and a vehicle appears, abort early - brake, signal right, tuck back in behind the cyclists - rather than accelerating out of it. Accelerating turns a hesitation into a head-on; the cyclists will forgive a close pass far more readily than the oncoming driver will.