Traffic Regulations and Speed Limits
Belgian speed limits you must memorise: 30 km/h in zones marked as such, 50 km/h in built-up areas (from the place-name sign to the sign showing the name crossed out), 70 km/h on most secondary roads outside built-up areas unless signed otherwise, 90 km/h on roads with a central reservation or two lanes each way outside built-up areas, and 120 km/h on motorways. Regional variations exist, so always read the sign in front of you rather than assuming.
Other core rules: drive on the right; overtaking is normally done on the left, with exceptions such as a queue of traffic or a tram you may pass on the right. Safety distances: keep at least two seconds behind the vehicle ahead, and much more in rain or on gravel. Seat belts are compulsory in all seats; children under 1.35 m need an approved restraint. Using a handheld phone while driving is prohibited. Dipped headlights are required at night and in tunnels, and in rain or fog when visibility drops.
Traps. Questions mix up the 70 and 90 limits, or place a 50 sign just outside a built-up area, which is valid and overrides the general rule. Another trap: the end-of-built-up-area sign restores the outside limit, which may be 70, not automatically 90. Also remember that a bus may use a bus lane and that a bus leaving a stop in a built-up area must be given priority by other traffic.
Rule of thumb: the place-name sign starts the 50 limit, the crossed-out name ends it. Worked example: you pass a place-name sign, drive 50, then pass a sign showing the name crossed out with a 70 sign below it: the limit is 70, not 90.