Overtaking a 25 km/h tractor before a crest where the line turns solid
You are riding at 80 km/h on a two-lane main road in eastern Finland on a dry June afternoon. Ahead, a tractor with a loaded trailer is doing 25 km/h and its left rear wheel is throwing mud onto the asphalt. About 200 m ahead the road rises to a crest, and from there the centre line changes: on your side the broken line ends and a solid line runs for the next 80 m. Between you and the crest there is a small side road on the left with a give-way sign facing it, and an unsheltered bus stop on the right. In your mirrors a car has been following at roughly 30 m. The tractor is 60 m ahead. Your bike pulls from 80 to 100 km/h in about six seconds in top gear, but a quick pass would need fourth. The wind is gusting from the left.
1. Decide whether you overtake the tractor here, and show the arithmetic and the hazard reasoning that lead to your decision.
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No. Closing speed is 100 − 25 = 75 km/h, about 21 m/s. I must accelerate, pull out, cover the 60 m gap plus roughly 10 m of tractor and trailer plus a 30 m safety margin before returning - about 100 m of clear road. At 21 m/s that is at least five seconds of full acceleration; realistically eight to ten seconds and well over 200 m once the acceleration phase is included. The crest is 200 m away and the line is solid on my side from there, so the road is not clear for the whole manoeuvre and I cannot see what is coming over the rise. Add the side road on the left, the bus stop on the right, mud reducing my grip, crosswind gusts, and a follower at 30 m who will be on top of me the moment I slow. I hold back at three seconds and pass after the crest where the broken line resumes.
2. What do the line markings mean, and would a completely clear view let you cross the solid line?
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A Finnish centre line is often a pair: a solid line and a broken line. You may cross the broken line when it is on your side and it is safe; a solid line on your side must not be crossed, and it is normally placed because visibility, a junction or a crest makes overtaking unsafe. Here the broken line ends and the solid line begins on my side, so from that point the manoeuvre is a violation, not merely a risk. But markings are a summary of a hazard, not the hazard itself: the general duty to overtake only when it is safe applies everywhere, and overtaking towards a crest, a junction or a bus stop is treated as careless driving even where no line forbids it. The line is the visible expression of the crest, not the only reason to stay behind.
3. Halfway through the manoeuvre the tractor's left indicator starts flashing. What do you do?
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A tractor with a trailer turning left swings wide: it may first move right, and the trailer cuts the corner. If I am already alongside on its left, I am in the space it is about to occupy, and my only escape routes are the oncoming lane and the verge. The correct action is to abandon the overtake before that point: stay behind, brake firmly but progressively in a straight line away from the mud, and give the tractor room to turn. This is exactly why the first decision matters - waiting behind at a proper gap turns this into a non-event. If I am already committed and alongside, I accelerate clear rather than brake level with the trailer, and I never try to squeeze between a left-turning vehicle and the verge.