Sand-Covered Roadworks Sign and a Police Officer's Signal
At 08:10 in Nouakchott you approach a junction on a two-lane avenue where roadworks have narrowed the carriageway for 200 m. A temporary 'road closed' sign stands half-buried in blown sand, its arrow board is switched off, and no cones remain upright. A police officer in a white shirt is standing at the junction. He waves you straight ahead, into the section marked closed. On the far side, a second officer is directing cars to turn left. You are 30 m from the junction, a taxi is close behind, and the morning traffic is building. Your view into the closed section is partly blocked by a parked lorry. You need to decide whether to obey the sign, the first officer, or the second officer, and how to move without creating a rear-end collision.
1. Which instruction has priority here: the half-buried sign, the first officer, or the second officer? Explain why.
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A police officer's signal overrides temporary road signs and traffic signals. That is the central rule: the sign is a static instruction, while the officer is controlling live traffic. The fact that the sign is half-buried in sand and its arrow board is off also makes it unreliable as a guide. However, there are two officers giving apparently conflicting directions. You should not treat the nearer wave as an absolute command until you understand the whole junction. Slow down, stop if necessary before entering the conflict area, and establish eye contact with the first officer. If the second officer is directing traffic away from the closed section, ask or signal for clarification rather than guessing. The safest reading is: obey the officer who is actually controlling your lane, but do not drive into a visible trench merely because someone waved.
2. What exactly should you do in the next 30 m to avoid a rear-end collision and still comply?
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Check your mirror early and brake progressively, not suddenly, because the taxi is close behind. Switch on your hazard lights briefly if you must slow sharply. Keep your lane position until you know which direction the officer intends; do not swerve around the sign into the path of oncoming traffic or the parked lorry. Approach at walking pace, with your foot ready to stop, and make eye contact with the officer. If he continues to wave you straight, proceed slowly into the closed section only while you can see that the surface is passable. If the second officer signals left, stop before the junction and let the conflicting signals resolve. A short pause is safer than committing to a narrow gap with blocked visibility.
3. You proceed as waved and then see a 1 m deep trench 20 m inside the closed section. What principle applies and what should you do?
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A visible hazard overrides a general wave. The officer may have intended you to proceed only as far as the next turning point, or he may not have seen the trench. You must stop safely before the trench, not drive into it, and not reverse blindly into following traffic. Put on hazard lights, keep passengers calm, and if possible send someone back to warn the taxi. Reversing is permissible only if you have a clear view and someone guiding you, or if the officer directs you. Otherwise wait for instructions. The reasoning is that the duty to avoid a known danger is stronger than a vague hand signal; a wave does not make an unsafe road safe.