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II. Speed

Chapter 6: Vehicles in Motion

General rules

All drivers must  adapt their speed according to the circumstances  and must take into account:

  • The  presence  of other users and in particular  pedestrians and cyclists.
  • The weather  (fog, snow, ice, wind, rain, etc.).
  • The layout of the premises  (elevated device, dangerous bend, speed bumps, etc.).
  • Clutter  (density, traffic jams, etc.).
  • Visibility  (hidden bend or summit of a hill, blinding sun, etc.).
  • The condition of the road  (holes in the road, ruts, etc.).
  • The condition of your vehicle  (quality of brakes and tires, etc.) and its  load.

It ‘s forbidden:

  • to travel at an abnormally low speed without valid reasons (the speed cannot constitute a hindrance to traffic)
  • to travel at excessive speed (speed cannot be a cause of accident)
  • to apply sudden braking without reason
  • to incite or provoke a driver to travel at excessive speed

Safety distance

  • The driver must, taking into account his speed, maintain a sufficient safety distance between his vehicle and the one he is following.

Predictable obstacle

  • The driver must in all circumstances be able to stop in front of a foreseeable obstacle

Approaching animals traveling on public roads

  • All drivers must slow down when approaching animals
  • It must stop when the animals show signs of fear

Speed ​​in urban areas

Speed ​​is limited to 50 km/h.

On certain public roads, a lower or higher speed limit may be imposed or permitted by signal C43.

In the Brussels metropolitan area, the speed is now limited to 30 km/h except where a higher limit is authorized.



  • In Flanders and the Brussels region the speed is limited to 70 km/h
  • In Wallonia the speed limit is 90 km/h
  • Unless a signal imposes another limitation on you.
  • On roadways with 2 directions of traffic divided into 4 lanes or more with a physical separator (rail, median, etc.) separating the 2 directions, the limit is 120 km/h
  • Unless a road sign imposes a lower speed limit on you.

Other limitations

Residential or meeting zone: 20 km/h

Occasional towing: 25 km/h

Zone 30 and around schools: 30 km/h  

Rue cyclable : 30 km/h  

The distances

Reaction distance:

  • This is the distance the vehicle travels between the moment the driver detects danger and the moment he begins to brake.
  • A driver’s reaction time is on average 1 second.
  • Reaction time depends from person to person. Using the phone while driving, alcohol, drugs and drowsiness are factors that will lengthen your reaction time.

How to calculate the reaction distance?


Example: you are traveling at 70 km/h your reaction distance will be 70/10 x 3 = 21 m.

Safety distance:

  • This is the distance you must maintain between your vehicle and the vehicle you are following

How to calculate the safety distance ?


Example: you are traveling at 70 km/h your safety distance will be 70/2 = 35 m.

On wet ground a greater distance is recommended, you divide your speed by 2 + half of the result obtained.

70 km/2 = 35 + 17.5 = 52.5 m

Braking distance:

(Speed/10) x (Speed/10)

Example: (70/10) x (70/10)

7 x 7 = 49 m

Stopping distance:

Reaction distance + braking distance

Example: At 70 km/h:

21 + 49 = 70m

I test my knowledge with questions

Chapitre 1: La réglementation