SlopeThailand

A road slope is a section of road that rises or descends over a particular distance. It may also be called a gradient, incline or decline.

A steep slope may be indicated by a warning sign showing an ascending or descending road. The sign may also display the gradient as a percentage.

A gradient of 10% means that the road rises or falls approximately 10 metres for every 100 metres travelled horizontally. It does not mean that the road is inclined at 10 degrees.

An ascent rises in the direction of travel, while a descent falls in the direction of travel. The same section of road is therefore an ascent in one direction and a descent in the other.

Not normally. It warns of a hazard rather than setting a numerical limit. Drivers must still respect the applicable speed limit and reduce their speed further when necessary.

Reduce speed before the descent, select a suitable gear and maintain a safe following distance. Avoid allowing the vehicle to gain excessive speed.

Use a gear that provides sufficient engine braking and helps keep the vehicle at a controlled speed. The appropriate gear depends on the vehicle, gradient and road conditions.

No. Coasting reduces engine braking and may make it harder to control the vehicle’s speed. Keep the transmission engaged while descending.

Continuous braking on a long descent can cause the brakes to become excessively hot and lose effectiveness. Select a suitable gear, control speed early and use the brakes progressively when needed.

Brake fade is a reduction in braking performance caused by excessive heat. It can occur when the brakes are used continuously during a long or steep descent.

Select a suitable gear before the engine begins to struggle and maintain a steady speed where possible. Be prepared for heavy or low-powered vehicles travelling slowly ahead.

Yes. Heavy vehicles, vehicles towing trailers and low-powered vehicles may slow considerably. Other drivers should maintain a safe distance and avoid impatient manoeuvres.

Do not overtake when the crest prevents you from seeing far enough ahead. Overtaking near a hilltop may also be expressly prohibited by local law, signs or road markings.

The road surface itself may hide approaching traffic, stopped vehicles, pedestrians or other hazards beyond the crest.

Some countries give priority to uphill traffic, while others rely on signs or ordinary obstruction rules. Drivers must follow local law and cooperate when passing is difficult.

Reduce speed and use a passing place where available. The driver who can reverse or move aside more safely should cooperate, subject to any applicable priority signs or local rules.

They reduce traction and make acceleration, braking and steering more difficult. Increase the following distance, use smooth controls and reduce speed before entering the slope.

Cyclists may travel slowly and move less steadily when climbing, while they may reach high speeds when descending. Drivers should leave sufficient space and avoid overtaking without a clear view.

Use the parking brake, select the appropriate gear or parking position and follow local rules concerning wheel position. Make sure the vehicle cannot roll into traffic.

Yes. A trailer increases the load on the engine and brakes and may affect stability. Drivers should use a suitable gear, maintain additional distance and avoid excessive speed.