Priority over oncoming trafficBelgium
Traffic rules
Belgium
23. Priority over oncoming traffic
Priority over oncoming traffic means that drivers travelling in one direction have priority through a narrow section of road over drivers approaching from the opposite direction. The rule is normally indicated by a priority sign facing one direction and a corresponding give-way sign facing the other.
Drivers with priority must still approach cautiously and must not force their way through when the passage is blocked or already occupied. The signs regulate priority through the narrow section, not speed, parking or priority at nearby intersections.
Wikimedia.org • Jean Housen • CC BY-SA
Which Belgian sign gives priority over oncoming traffic?
Traffic sign B21 indicates that drivers have priority over drivers approaching from the opposite direction through a narrow passage.
Road narrowing, oncoming drivers have to give way.
Signal routier B21 • Passage étroit. Priorité de passage par rapport aux conducteurs venant en sens opposé.
Verkeersbord B21 • Smalle doorgang. Voorrang ten opzichte van de bestuurders die uit de tegenovergestelde richting komen.
Road narrowing, give way to oncoming drivers.
Signal routier B19 • Passage étroit. Obligation de céder le passage aux conducteurs venant en sens opposé.
Verkeersbord B19 • Smalle doorgang. Gebod voorrang te verlenen aan de bestuurders die uit de tegenovergestelde richting komen.
How can you recognise Belgian sign B21?
B21 is a rectangular blue sign showing a large white arrow in your direction and a smaller red arrow representing oncoming traffic.
Which sign does traffic at the opposite end see?
Oncoming drivers normally face traffic sign B19, which requires them to give way to drivers approaching from the opposite direction.
What does Belgian sign B19 mean?
B19 means that drivers must give way to oncoming drivers through the narrow passage.
Are B19 and B21 used together?
Yes. When B19 is placed at one end of the passage, B21 is placed for traffic approaching from the other direction.
When may Belgium use B19 and B21?
Under the current placement rules, they may be used where two cars cannot pass one another and drivers can see the entire narrow passage from one end to the other.
Does B21 make the road one-way?
No. The road remains open in both directions. B21 determines which direction has priority when opposing vehicles cannot pass simultaneously.
Must you stop at B21?
No. You may continue when the passage is clear, but you must approach cautiously and stop when necessary to avoid danger.
May you enter when an oncoming vehicle is already inside?
You should not force your way into the passage. Slow down or stop and allow the occupied passage to clear, even though B21 normally gives your direction priority.
Does B21 allow you to force another vehicle to reverse?
No. Priority does not justify creating a dangerous situation. Drivers must cooperate when another vehicle is already committed to the passage.
What if both drivers arrive at the same time?
The driver facing B21 may normally proceed first. The driver facing B19 must give way.
Does reaching the narrowing first automatically give priority?
No. Priority is determined by B19 and B21 rather than simply by which vehicle arrives first.
Does B21 apply to cyclists?
Yes. Cyclists are drivers under Belgian traffic law and are included in the priority arrangement unless another traffic control provides otherwise.
Must you leave room when passing a cyclist?
Yes. Drivers must maintain at least one metre inside a built-up area and 1.5 metres outside a built-up area. If that distance cannot be maintained in the narrow passage, the driver must wait.
What if a truck or bus approaches?
Large vehicles may require the full available width. Reduce speed and wait outside the passage when necessary, even when you have priority.
Does B21 impose a speed limit?
No. The applicable regional, zonal or posted speed limit remains in force. Drivers must nevertheless adapt their speed to the limited width and visibility.
Does B21 give priority at a nearby intersection?
No. It applies only against traffic approaching from the opposite direction through the narrow passage. Intersection priority is determined separately.
May you overtake near B21?
B21 does not itself prohibit overtaking, but overtaking is unsafe when the available width or visibility is insufficient. Other signs or road markings may also prohibit it.
May you stop or park in the narrow passage?
B21 creates no separate parking rule, but stopping or parking is prohibited when it would create danger, obstruct traffic or leave insufficient free passage.
How much free road width must remain when parking?
Belgian parking rules require at least three metres of free carriageway to remain available.
What if temporary traffic lights are installed?
Follow the active traffic lights. They control the alternating traffic movement and take precedence over the fixed B19 and B21 arrangement at that location.
What if a police officer or road worker directs traffic?
Follow the instructions of an authorised person. Those instructions take precedence over traffic signs and ordinary traffic rules.
Will B21 remain in Belgium’s new road code?
Yes. The Code of the Public Road taking effect on 1 June 2027 retains B21 for priority over oncoming drivers and B19 for the direction that must give way.
