The tractor, the broken line and the hidden side road
You are riding a 250 cc motorcycle north on a national secondary road at about 70 km/h in dry daylight. Ahead, a tractor towing a loaded trailer is doing 25 km/h. The centre line changes to a continuous white line with a broken white line on your side, and a sign indicates a side road joining from the left about 120 m beyond the tractor. You can see roughly 150 m of clear road ahead before it curves left behind a hedge. Two cars are following you at a normal distance. The tractor's right indicator begins to flash and it slows further.
1. What does the line marking allow you to do, and should you overtake now?
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The marking is a permission, not an instruction. The broken line on your side means you may cross the continuous line to overtake when it is safe - it does not make this moment safe.
Reasons to hold back:
- The tractor is indicating right and slowing. It may be turning into the side road or a field entrance. A vehicle turning right across your path is the classic overtaking collision, and the trailer will swing wide.
- Sight line arithmetic. You close on the tractor at about 45 km/h (roughly 12 m/s). A safe pass needs the full overtake plus a margin to return left plus a buffer in front of the tractor. A clear 150 m to a bend that hides oncoming traffic behind a hedge is not 150 m of guaranteed clear road.
- The two cars behind may follow you out, turning one gap into three vehicles in the same space.
Decision: stay behind, let the tractor commit, and reassess after the side road with a genuine, seen-to-be-clear stretch.
2. You decide to wait. Where do you put the motorcycle, and how do you manage the two cars behind?
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- Gap: hold at least 3 seconds behind the tractor - more than feels natural at 25 km/h. It gives you a view past the trailer and room to stop if the tractor brakes hard.
- Position: slightly left of the centre of your lane. Not hugging the verge (gravel, drains, and it invites a following car to squeeze past you and the tractor together), and not in the centre where you block the view of drivers behind and tempt them into a blind pass.
- Visibility: stay where the tractor driver can pick you up in the mirrors. Assume they are watching the field gate, not you.
- The cars behind: when you first slow, a brief touch of the brake light warns them. If one starts to overtake, do not race it - ease off, widen your gap and let it go. The risk transfers to them; the gap in front of you is your protection.
3. The tractor turns right into the side road but stops with its trailer blocking the left half of your lane. What do you do, and what must you not do?
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This is the exact situation the hold-back was for.
Do:
- Check the mirror before braking, then slow early and progressively rather than arriving at the trailer at speed.
- Stop short with room for the trailer to complete its swing; give the driver time to clear.
- Once the lane is clear and you have checked what is behind, proceed.
Do not:
- Swing right around the front of the tractor. That puts you across the continuous line into the path of anything coming, and the cab and trailer block your view of exactly that traffic.
- Squeeze past on the inside. You would be off the running surface, on a soft or muddy verge.
- Assume the tractor driver has seen you simply because you can see them.