Legal obligations when facing a signaled danger

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A danger sign legally obliges you to adapt speed and attention: what that means in practice for a driver in Belgium.

Cover, Legal obligations when facing a signaled danger

Lesson objectives

Understand legal obligations when facing a danger signaled by a triangular sign Adapt your speed and vigilance according to the type of danger announced Apply braking and positioning rules before entering a dangerous zone

When a danger is signaled: your obligations

A danger signal does not forbid anything and does not oblige anything specific, but it is not merely information either. It triggers the general obligation of article 10.1, 1° : adjust your speed according to the presence of other users, weather conditions, the layout of the place, its congestion, traffic density, visibility range, road condition, the condition and loading of your vehicle , "your speed can be neither a cause of accident nor a hindrance to traffic". This is where the legal obligation lies: the signal establishes that the danger was signaled , therefore foreseeable. And article 10.1, 3° requires being able to stop before a foreseeable obstacle .

Danger sign

Danger signal: triangular sign with red border on white background, placed approximately 150 m from the dangerous location (art. 66.2), except A45 and A47, placed at the level crossing. Any other distance, as well as the length of the dangerous section, is indicated by an additional sign (art. 66.2 and 66.3).

Dangerous curves: brake before, not in them

A1a

Caution, dangerous left turn ahead. This sign announces a left turn that presents a danger, either because of its tight radius or because of poor visibility. You must slow down before entering it, stay well in your lane and avoid overtaking. A vehicle may appear head-on at the exit of the turn.

A1b

A1b, Dangerous right turn. This sign announces a right turn considered dangerous. Slow down well before entering it, keep your vehicle in your lane and remain vigilant at the exit, as a vehicle may appear head-on if it has cut its turn.

A1c

Double turn or succession of more than two turns, the first to the left. Several turns follow in a zigzag pattern, starting with the left. Ease off before the first turn and maintain a moderate speed until the end of the series.

A1d

Double bend or succession of more than two bends, the first to the right. The road will wind starting to the right. Slow down and remain vigilant over the entire area, even between bends. Avoid any overtaking.

Golden rule: brake before entering the turn, never in it. Braking in a turn destabilizes your vehicle and reduces tire grip. Once in the curve, maintain a constant and controlled speed. As soon as you see a dangerous turn sign, ease off the accelerator gradually to arrive at the curve with an appropriate speed.

Anticipate: starting 150 m before the turn, begin to reduce your speed. This gives you time to adapt without emergency braking.

Dangerous turn on mountain road

Slopes: downshift to maintain control

A3

A3, Steep descent. The road will descend sharply. A percentage indicates the gradient, for example ten percent. Downshift before the descent to use engine braking and maintain a good distance from the vehicle in front of you. Avoid continuous braking, as the brakes risk overheating.

A5

A5, Steep climb. A significant hill awaits you. Downshift to maintain power and be patient, as heavy vehicles and buses may travel much more slowly. Do not attempt to overtake blindly at the top of the hill.

Facing a dangerous descent , downshift before going down it. This uses engine braking and prevents brake overheating. Going uphill, downshift to maintain power and avoid stopping along the way. Do not rely solely on brakes: they can wear out or overheat. Engine braking is your main ally on slopes.

Engine braking

Speed reduction technique by downshifting (moving to a lower gear). The engine brakes the vehicle without wearing the brakes. Essential when descending.

Narrowings: center yourself

A7a

Sign A7a: roadway narrowing on both sides. The width of the road decreases on the left and right. Slow down, center your vehicle on the lane and be alert to vehicles coming towards you. There will be less space to pass each other.

A7b

A7b, Road narrowing on the left side. The left lane narrows. If you are driving there, carefully move to the right. Indicate and check your blind spot before changing lanes.

A7c

A7c, Roadway narrowing. The roadway narrows on one side: slow down, reposition yourself in time, watch for vehicles coming towards you. Not to be confused with the lane ending of article 12bis, which assumes a lane that ends and heavily reduced traffic. Here the obstacle rule of article 15.2 applies, or signals B19 and B21 if present.

When the roadway narrows, slow down and center your vehicle. Maintain a stable trajectory in the middle of your lane. Watch out for vehicles coming in the opposite direction: space is limited.

Obstacles on the roadway: slow down well in advance

A13

A13, Bump or dip. A significant bump or dip crosses the road. Slow down well in advance to cross the obstacle smoothly, preserve your suspension and passenger comfort.

A14

A14, Raised device. It announces a speed bump, plateau or cushion built across the roadway. Article 22ter.1 sets the rule with a figure: drivers must approach these devices with extra caution and at moderate speed, so as to cross them at a speed not exceeding thirty kilometres per hour. The same obligation applies when the device is announced by signal F87, when it is only announced by an A14 at an intersection, or when it is located in an area delimited by signals F4a and F4b.

A speed bump, a dip or a raised device crosses the road. Slow down well in advance to cross the obstacle at low speed. Passing too quickly can damage your vehicle or cause you to lose control.

Slowing down before an urban speed bump

Slippery surfaces: maximum vigilance

A15

A15, Slippery road. The road may be particularly slippery in case of rain, ice, gravel or fallen leaves. Avoid sudden braking and sharp steering movements. Increase safety distances and adapt your speed to conditions.

A17

A17, Gravel projection. The road has been recently resurfaced. Small stones may be projected by wheels. Slow down to avoid damaging your windscreen and that of vehicles following you. Maintain a good distance.

The roadway can be slippery for several reasons: rain, ice, fresh gravel, dead leaves. Avoid sudden braking and acceleration . Increase safety distances and maintain a moderate and steady speed.

Vulnerable road users: slow down and be ready to stop

A21

A21, Pedestrian crossing. A pedestrian crossing is ahead. Slow down and be ready to stop to let people who are crossing or waiting at the roadside pass.

A23

You are approaching an A23 zone, a place specially frequented by children. It may be a school, playground or daycare. The presence of children is frequent there. Adopt increased vigilance, as a child may appear without warning. Ease off the accelerator and be ready to brake.

A25

A25, Crossing for cyclists and two-wheeled moped riders, or outlet of a cycle path onto the roadway. Expect to see bicycles or mopeds crossing or entering the road. Slow down and prepare to give way if necessary.

A27

A27, Crossing of large game. The letter A designates the series of danger signals, not a motorway. Deer and wild boar cross mainly at dawn, dusk and night, and rarely alone. Article 10.3 requires slowing down when approaching animals on the public road. In case of unavoidable collision, brake firmly without steering sharply.

A29

A29, Crossing of livestock. Danger signal, unrelated to a numbered road. Article 10.3: every driver must slow down when approaching draft, pack and riding animals or livestock on the public road, and stop when these animals show signs of fear. Do not use the horn.

Pedestrians, children, cyclists, animals: these users are unpredictable. As soon as you see a sign indicating them, slow down to moderate speed and be ready to stop. Never assume they will stay out of the way.

Approach a pedestrian or cyclist crossing at moderate speed , so as not to endanger users already engaged. Be ready to brake immediately.

Level crossings: extreme vigilance

A41

A41, Level crossing with barriers. Danger signal from series A, not a motorway. Article 20.3 prohibits proceeding as soon as the barriers are moving or closed, as soon as the red lights are flashing, or as soon as the sound signal is operating.

A43

A43, Level crossing without barriers. Danger signal from the A series. Article 20.2 requires extra caution and only proceeding after ensuring that no rail vehicle is approaching.

A45

A45, Level crossing with a single railway line. This proximity sign indicates that the level crossing is just ahead, with a single track. Check for trains and cross the rails without stopping on them.

A47

A47, Level crossing with two or more railway lines. Caution: there are multiple tracks, so multiple possible trains that may arrive from different directions. Check each track before crossing and only proceed if the entire crossing is completely clear.

A49

A49, Crossing of the public road by one or more railway lines established on the roadway. Tram or train rails cross the road at ground level. The code does not give the rail vehicle a "priority": it sets its own rules, crossing is done on the right, except where impossible (art. 15.4), overtaking is done on the right even when stopped for boarding (art. 16.9), and stopping and parking are prohibited where the passage of rail vehicles would be obstructed (art. 25.1, 6°).

A train can arrive at very high speed. Slow down sharply and be ready to stop completely. Even if the barriers are not down, a train may arrive. Never attempt to cross if you have any doubt.

A level crossing without barriers (A43) leaves all judgment to the driver: article 20.2 requires extra caution and only proceeding after ensuring that no rail vehicle is approaching . The same requirement applies when an equipped crossing has its signals out of service . Note what the text does not say: it does not require stopping. This is only mandatory if a B5 signal is placed, but in practice, ensuring that no train is approaching often requires it.

Other hazards: adapt your reaction

A9

A9, Movable bridge. The letter A designates the series of danger signals: there is no motorway A9 here. The bridge opens to let boats pass; slow down and be ready to stop. Two red lights flashing alternately mean prohibition to proceed, for all users (art. 64.2).

A11

A11, Outlet onto a quay or bank. Warning: the road ends at the water's edge, whether it is a canal, port or river. Slow down significantly and be very careful. Especially at night or in poor visibility, as there is a real risk of falling into the water.

A19

A19, Caution, falling rocks. Rocks may fall from the cliff onto the road or already be on the roadway. Slow down, watch the roadway carefully and be ready to avoid an obstacle. The risk is increased after heavy rain or during freeze-thaw periods.

A31

A31, Construction work. Construction is underway on the roadway or nearby. Reduce your speed, respect temporary signage and be alert to workers and construction vehicles that may enter or exit the work area.

A33

A33, Traffic light signals. Traffic lights are ahead. Ease off now so you can stop without difficulty if the light turns orange or red.

A37

A37, Lateral wind. Gusts from the side can destabilize your vehicle, especially if you are towing a trailer, driving a motorcycle, van or heavy vehicle. Hold the steering wheel firmly and anticipate wind gusts near bridges and open spaces.

A39

A39, Traffic allowed in both directions after a one-way section. The road you were leaving as one-way becomes two-way again. You will now meet vehicles head-on. Keep to the right, reduce your speed and adjust your trajectory.

A50

A50, Queue. This sign announces an area where queues form frequently: sudden stops, sudden slowdowns. Ease off the accelerator as soon as you see it and increase the distance from the vehicle ahead. This is also where article 9.8 applies: in case of queue formation, drivers form an emergency lane, each moving to their side at two lanes, the left lane to the left and all others to the right beyond.

A51

A51, Danger not defined by a special symbol. There is a danger ahead, but which does not correspond to other signs. Its exact nature is specified on an additional sign placed below, for example "frequent fog". Exercise extra caution and adapt your driving.

Each danger has its own logic. A movable bridge requires particular vigilance. Falling rocks demand constant attention. Frequent traffic jams require anticipating slowdowns. Read the sign, understand the danger, and adjust your speed and vigilance accordingly.

Key principles to remember

The 150 metres separating you from the danger are a preparation time, not a margin for manoeuvre. Use them to: gradually reduce your speed, article 10.2 moreover prohibits sudden braking not required by safety reasons ; signal a notable slowdown by means of brake lights , or failing that by an arm gesture (art. 10.2) ; adapt your position and increase the safety distance ; maintain this vigilance until you have passed the danger, a signal does not cease to apply because nothing came up.

The danger signal is placed at approximately 150 m (art. 66.2) ; the A45 and A47 are exceptions. A different distance, or the length of the section, appears on an additional sign . It prohibits nothing: it makes the danger foreseeable , which engages article 10.1 , adjust your speed according to circumstances, and be able to stop before a foreseeable obstacle . Bends : slow down before , never in them. Overtaking prohibited at the top of a hill and in a bend if visibility is insufficient , except if it can be done without crossing the continuous line (art. 17.2, 3°). Descent : downshift and use engine braking rather than continuous braking. Animals (A27, A29): slow down, and stop if they show signs of fright (art. 10.3). Vulnerable road users (A21, A23, A25): moderate speed and stop if necessary (art. 40.4 and 40ter). A51 : danger not defined by a symbol; its nature is specified by an additional sign. Slow down, yes, but without sudden braking not required by safety (art. 10.2).

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