Traffic Laws and Driving Rules
This domain covers the rules you must obey continuously: speed, following distance, overtaking, restraint use, phone use, lighting, horn use, load limits and the documents you must carry. The examiner wants the posted sign to govern your answer, not habit.
Speed and distance
Built-up areas are generally limited to 50 km/h unless a lower sign applies, with 30 km/h zones near schools and markets. Outside towns the limit is commonly 90 km/h on the main network, lower on pistes and sand. A sign always overrides the general figure. Keep a two-second gap in dry conditions and double it on sand, in rain after a wadi flood, or in dust; at 90 km/h that is roughly 50 m, and about 100 m when traction is poor.
Overtaking and positioning
Overtake on the left. Never overtake at a pedestrian crossing, on a junction, on a crest, in a bend, or where a continuous line or a sign forbids it. Do not overtake a vehicle that is itself overtaking. Drive on the right, use the right-hand lane unless overtaking, and never drive on the soft shoulder to let faster traffic past - the edge collapses.
Restraints, phones and lights
Seat belts are compulsory for all occupants, and children need an approved restraint. A phone may only be used hands-free. Dipped headlights are required at night and in dust, rain or poor visibility; fog lamps are for fog only. The horn is a danger warning, not a way to hurry people, and in town at night it should be avoided. Alcohol and driving do not mix: Mauritanian law and practice treat drink-driving severely, so the only safe figure is zero.
Worked example
You are following a truck at 90 km/h and the road surface turns sandy after a flood. Reasoning: 90 km/h is 25 m per second, so two seconds is 50 m; doubling for reduced grip gives about 100 m. You drop back to 100 m and slow further, because the truck's spray and the sand both cut your view of the road ahead.
Traps that cost marks
Quoting the general limit when a sign shows something else; treating the two-second rule as fixed in bad conditions; and driving with hazard lights on while moving.