SlopeFlanders

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15. Slope

A slope is a section of road that rises or descends noticeably. A steep slope can affect vehicle speed, braking distance, traction, visibility and the ability of heavy or low-powered vehicles to maintain a steady speed.

Warning signs may indicate a steep ascent or dangerous descent and may show the gradient as a percentage. Drivers should adjust their speed early, select a suitable gear and remain prepared for slow vehicles, bends and changing road conditions.

Steep descent warning sign on the cobblestone Kemmelberg. (Kemmel, Belgium)
Wikimedia.org • Astro • CC0
Which Belgian signs warn of a steep slope?

Traffic sign A3 warns of a dangerous descent, while traffic sign A5 warns of a steep ascent.

Warning for a steep descent. Warning for a steep descent.

Signal routier A3 • Descente dangereuse.

Verkeersbord A3 • Gevaarlijke daling.

Warning for a steep ascent. Warning for a steep ascent.

Signal routier A5 • Montée à forte inclinaison.

Verkeersbord A5 • Steile helling.

What changes for steep ascents and descents under Belgium’s new Road Code?

Belgium’s new Code of the Public Road takes effect on 1 June 2027. The warning signs keep their existing numbers: traffic sign A3 warns of a dangerous descent and traffic sign A5 warns of a dangerous ascent. The percentage shown on the sign indicates the gradient of the slope. Under the new Road Code, the meaning of A5 is broadened from a “steep ascent” to a dangerous ascent.

Warning for a steep descent. Warning for a steep descent.

Signal routier A3 • Descente dangereuse. Le pourcentage indique l’inclinaison de la pente.

Verkeersbord A3 • Gevaarlijke daling. Het percentage duidt de hellingsgraad aan.

Warning for a steep ascent. Warning for a steep ascent.

Signal routier A5 • Montée dangereuse. Le pourcentage indique l’inclinaison de la pente.

Verkeersbord A5 • Steile helling. Het percentage duidt de hellingsgraad aan.

What does Belgian traffic sign A3 mean?

Sign A3 warns that the road ahead descends steeply or dangerously in the direction of travel.

What does Belgian traffic sign A5 mean?

Sign A5 warns that the road ahead rises steeply in the direction of travel.

What does the percentage on a Belgian slope sign mean?

A displayed gradient of 10% means that the road rises or falls approximately 10 metres over a horizontal distance of 100 metres. It does not represent an angle of 10 degrees.

When may A3 or A5 be installed in Belgium?

Under the current Belgian placement rules, these signs may be used for carriageways with an ascent or descent of at least 7%.

Does A3 or A5 impose a speed limit?

No. They are warning signs. Drivers must respect the applicable maximum speed and reduce their speed sufficiently for the gradient, visibility, traffic and road conditions.

How should you drive down a steep Belgian road?

Reduce speed before the descent, select a suitable gear and keep the vehicle under control. Drivers must always be able to stop before a foreseeable obstruction.

Should you descend in neutral?

No. Keep the transmission engaged so that engine braking helps control the vehicle. Coasting can allow the vehicle to gain speed and places more demand on the brakes.

How should you drive uphill?

Select a suitable gear early and maintain a controlled speed. Expect heavy vehicles, agricultural vehicles or vehicles towing trailers to travel more slowly.

May you overtake near the top of a Belgian slope?

Left-side overtaking of a team, a two-wheeled motor vehicle or a vehicle with more than two wheels is prohibited when approaching the crest of a slope with insufficient visibility. An exception applies where overtaking can be completed without crossing the continuous line separating opposing traffic.

May you stop or park near the crest of a slope?

No, when visibility is insufficient. Stopping and parking on the carriageway near the top of a slope are prohibited where the vehicle would be difficult for approaching road users to see.

Does uphill traffic automatically have priority in Belgium?

No. Belgian law does not give uphill traffic a universal priority solely because of the slope. Drivers must follow priority signs and the ordinary crossing rules.

Who must give way when an obstruction narrows the road?

The driver whose passage is obstructed must slow down and, when necessary, stop to allow approaching road users to pass.

Does a slope sign change priority at an intersection?

No. Signs A3 and A5 warn of the gradient but do not alter intersection priority. Traffic lights, priority signs and the ordinary priority rules remain applicable.

Must you reduce speed below the posted limit?

Yes, when necessary. Belgian drivers must adapt their speed to the road layout, visibility, traffic, weather, vehicle condition and load.

Why should heavy vehicles leave additional distance?

Heavy vehicles require more distance to slow down and their brakes may heat up during long descents. Additional following distance provides more time to react and brake progressively.

How should cyclists be passed on a Belgian slope?

Drivers must leave at least one metre inside a built-up area and 1.5 metres outside a built-up area. They should wait when the crest, bend or oncoming traffic prevents a safe pass.

How should you secure a parked vehicle on a slope?

Apply the parking brake firmly, select a gear or the transmission’s parking position and take every necessary precaution to prevent the vehicle from moving or being misused.

1 Flanders 2 Motorway 3 Expressway 4 Residential area 5 Built-up area 6 Zone 7 Speed limit 8 Bike path 9 Cycling street 10 Pedestrian zone 11 Speed bump 12 Customs 13 One-way traffic 14 Quay 15 Slope 16 Bus lane 17 Dead end 18 Stop sign 19 Give way 20 Roundabout 21 Priority road 22 Road narrowing 23 Priority over oncoming traffic 24 Give way to oncoming traffic 25 Pedestrian crossing 26 Railway crossing 27 Mandatory direction 28 Turn prohibition 29 School area 30 Crossing animals 31 Rockfall 32 Curve 33 Chevron 34 Wrong-way driving 35 Roadworks 36 Height limit 37 Width limit 38 Weight limit 39 Radar speed sign 40 Selective barriers 41 Intersection direction sign 42 Priority at the next junction 43 Traffic lights 44 Pedestrian lights 45 Driving licence 46 Location marker 47 Traffic mirror 48 International border 49 Cycling route 50 Parking 51 No parking 52 Kiss and ride 53 Parking meter 54 Traffic management 55 Reversing 56 Uncontrolled crossroad 57 Road surface 58 Ring road 59 Cycle highway 60 Licence plate 61 Charging station 62 Dangers 63 Turn on red 64 Identity card 65 Fire risk 66 Pedestrian 67 Moped 68 Car 69 Truck 70 Bus 71 Police 72 Ambulance 73 Tram lights 74 European emission standard 75 Pothole 76 Public square 77 Path 78 Particulates 79 Air pollution 80 Rush hour 81 Road code 82 Street gutter 83 Cargo bike 84 Forestry vehicle 85 Construction vehicle 86 Semi-trailer truck 87 Trolleybus 88 Speed pedelec 89 Delivery vehicle 90 Idling 91 Tow truck 92 Four-wheel drive 93 No vehicles 94 Bicycle 95 Motorcycle equipment 96 Railcar 97 Rail track 98 Public transport 99 Caravan 100 Trailer ...