The Tractor Driver Waves You Past on a Solid Line
You are driving a small hatchback on a two-lane road outside Erdenet. The posted limit is 80 km/h, but you are stuck behind a slow tractor carrying hay at 35 km/h. The centre line is solid for the next 200 m; after that it becomes dashed. The road climbs to a crest about 150 m ahead, and you cannot see beyond it. A vehicle behind you is tailgating and flashing its headlights. The tractor driver waves you past with an arm signal. Oncoming traffic has been light, but one car passed in the opposite direction less than a minute ago. It is -15°C and the road is partly icy in the shade. Your passenger urges you to go. You have been behind the tractor for 4 km.
1. The tractor driver waves you past. Should you overtake now?
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No. The tractor driver's arm signal is a courtesy, not a legal clearance. The solid centre line prohibits crossing, and the crest about 150 m ahead hides oncoming traffic. A car passed in the opposite direction less than a minute ago, so another may appear at any moment. Overtaking at a crest is a classic head-on crash scenario.
Even after the line becomes dashed, the crest still blocks your view. You must wait until you can see a clear gap, the line permits overtaking, and you can complete the manoeuvre at a safe speed. The passenger's urge and the tailgater's flashing do not change the law or the physics.
2. What factors determine a safe overtake here, and when would the safe moment arrive?
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The factors are: the legal marking, forward visibility, road surface, your vehicle's acceleration, the length of the overtake, oncoming traffic, and escape space. Here the solid line and the crest rule out an overtake immediately. The shaded ice means you cannot brake or steer sharply if the overtake goes wrong.
The safe moment comes after the crest, on a straight section with a dashed line, no oncoming vehicle in sight, and enough gap to return to your lane without cutting in. At 80 km/h versus 35 km/h, the closing speed is 45 km/h, or 12.5 m/s. Passing a 10 m tractor with a 20 m return gap might take two to three seconds in good conditions; on ice, allow more. If you cannot see that far, do not start.
3. How should you handle the tailgating vehicle behind you?
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Do not speed up, brake-check, or wave angrily. Maintain your speed and increase your gap to the tractor so that you can brake gently if the tractor slows. A gentle, predictable drive gives the tailgater less excuse to take risks.
If the tailgater persists, pull over at a safe turnout and let them pass when it is legal to do so. Do not overtake just to escape pressure. That is how drivers end up committed to an overtake they cannot complete.