The waving lorry driver, the solid line and the crest
You are driving a hired 1,300 cc saloon from Nairobi to Machakos on a two-lane road. Four adults are aboard plus about 60 kg of luggage in the boot, and the rear springs are visibly down. Ahead, a loaded lorry is grinding up a long hill at 20–25 km/h and you have been behind it for six minutes. A continuous solid white line runs down the centre of the road for the next 400 m and over the crest. The lorry driver switches on his right indicator, then puts his hand out of the window and waves you past. Beyond the crest you can already see the tops of two oncoming lorries. Just before the crest the carriageway narrows at an old culvert where the shoulder has broken away. A saloon behind you has been flashing its headlights and sitting close to your bumper for the last kilometre.
1. The lorry driver has signalled and waved you through. Do you go? Give the legal position and the practical calculation.
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No.
The law: a continuous solid white line down the centre means you must not cross it and must not overtake. The offence, if it happens, is committed by the overtaking driver - not by the lorry driver who waved. A wave from another driver transfers no legal authority and no liability. If it goes wrong, 'he waved me past' is not a defence; it is an admission that you took your instructions from a stranger instead of from the road.
The practical calculation:
- Two oncoming lorries are already visible over the crest. At 25 km/h you would be pulling out into a closing speed of perhaps 80–90 km/h, with the oncoming vehicles hidden for part of the manoeuvre.
- The car is a loaded 1,300 cc with five adults and 60 kg of luggage going uphill. Acceleration is poor, so a safe overtake would need 300–400 m of clear road, not 400 m of solid line.
- The culvert narrowing leaves you nowhere to go if it goes wrong - no shoulder, no escape.
- Braking distance home is also longer, because the car is fully loaded.
The rule of thumb: if you cannot see the whole overtake plus a margin of clear road, and complete it before the solid line or the crest, you do not start it. Here you cannot see it and you cannot complete it.
2. What is the correct plan for the next 400 m, and what do you do about the car behind you?
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Plan for the next 400 m:
- Drop back to a gap of at least 3–4 seconds behind the lorry. Two reasons: you can see past it, and the car behind can see past you and see the road ahead.
- Hold a steady speed rather than stopping and starting - you want to arrive at the far side of the crest with the car already in a position to use a gap if one opens.
- Keep left, away from the culvert narrowing.
- A brief period of hazard lights to mark a slow-moving queue is accepted practice on Kenyan trunk roads, but switch them off once traffic behind has adjusted; do not drive for kilometres with them flashing.
The car behind:
- Do not brake-check it. Do not accelerate to 'show' it either.
- If it pulls out across the solid line, ease off and let it go. Do not race it, and be ready to brake hard if it has to cut back in ahead of you or the lorry.
- Its pressure does not change the law or the physics. Your job is to keep your own decision clean.
Once over the crest and onto a broken line with a clear view, reassess from scratch: if there is a genuine gap, use the method below; if not, drop back again and wait.
3. You reach a straight, flat stretch with a broken line and 500 m of clear view. Walk through how the overtake is actually executed in this car, and give the conditions that would make you abandon it.
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Executing it in a loaded 1,300 cc car:
- Mirrors and blind spot first; signal in good time.
- Drop a gear before pulling out, so you are already in the power band and do not lose the first two seconds of the overtake shifting.
- Build speed while still behind the lorry rather than pulling out at 25 km/h and trying to accelerate in the oncoming lane.
- Commit only when the whole manoeuvre plus a margin fits inside the road you can see to be clear - not just the road you can see.
- Leave at least a metre of lateral clearance; more if the lorry is swaying under load.
- Return to the left only when you can see the lorry's cab in your interior mirror. Do not cut in - a loaded car needs a longer braking distance, and the lorry does too.
Abandon the overtake if:
- Anything appears over the horizon, out of a side road, or a third vehicle joins the picture.
- The speed differential is not there - if you are not clearly gaining, you will be stuck alongside.
- The gap ahead starts to close, for any reason.
Abandoning means a firm, controlled brake and slotting back behind with your indicator on - not forcing the lorry to brake for you.