Driving on hills

You need to understand how driving uphill and downhill can affect your control of the vehicle.

• Going uphill, your engine has to use more power to overcome gravity and drive the vehicle up the hill.
• Going downhill, gravity will cause the vehicle to increase speed. The steeper the hill, the greater this effect.

In each case, the effect on the controls is different from driving on the level.

Going uphill

When going uphill

• you’ll find it more difficult to maintain or increase speed. The engine has to work harder to make the vehicle go faster
• your brakes will slow the vehicle down more quickly
• you might need to change to a lower gear to maintain your speed. If you release the accelerator or push the clutch pedal down, your speed will drop more quickly than it would on the level. Changing to a lower gear should be done without hesitation, so you don’t lose too much speed
• remember to apply the parking brake before you release the footbrake when stopped, otherwise you might roll back.

Look for signs

On steeper hills, you’ll see warning signs telling you how steep the upward slope is. The figures usually measure the gradient in percentage terms (or very occasionally as a ratio): the higher the percentage, the steeper the hill.

You may see another rectangular sign telling you the length of the hill and further information.

Watch out for slow-moving, heavy vehicles. They may be travelling much more slowly than other traffic and their large size can make them difficult to overtake safely.

Assess the hill

If the hill is very steep, think ahead and consider changing to a lower gear. If you do need to change gear, make sure you do so in good time.

Don’t stay in a high gear to try to keep your speed up. Your vehicle will climb better in a lower gear.

Separation distance

Keep well back from the vehicle ahead.

• If you don’t hold back and the vehicle ahead suddenly slows or stops, you may have to brake harshly.
• Holding back may enable you to keep going gently while the vehicle ahead regains speed. This is safer and can also help to avoid congestion.

Overtaking

It’s usually more difficult to overtake when travelling uphill. Oncoming traffic may be travelling faster than usual and may take longer to slow down or stop.

On a dual carriageway, overtaking is easier because there’s no danger from oncoming traffic. Here you should keep a lookout for others following behind you who can overtake with ease. Don’t block their progress.

Going downhill

When going downhill

• you’ll find it more difficult to slow down and the brakes will have less effect
• it’s harder for the engine to hold the vehicle back. In higher gears it won’t do so at all
• you should avoid coasting, either out of gear or with the clutch pedal down, because you’ll have no engine braking. Without engine braking your vehicle will pick up speed more easily, and this could result in you having less control of the vehicle
• try to avoid braking on a bend
• get into a lower gear in good time, particularly if there’s a bend ahead. This will increase the engine braking and help to control the vehicle’s speed
• use the correct combination of lower gear and careful use of the footbrake to keep control of your speed.

Look for signs

The steep hill (downwards) warning sign will give you the gradient of the downward slope.

You might also see a rectangular sign advising use of a low gear. The steeper the hill, the lower the gear.

Assess the hill

Use the sign to help you think ahead. If the route is unfamiliar, or a bend limits your view of the road, change down before you begin to descend. Change smoothly and without hesitation.

Separation distance

Always keep the correct separation distance from the vehicle ahead.

If you don’t hold back and the vehicle ahead suddenly slows down or stops, you’ll have to brake very hard. The driver behind will get very little warning.

If you hold back, you’ll have time to reduce your speed more gradually.

Adjust your speed

On steep hills, you’ll normally need to reduce speed. Change down to a lower gear to give yourself more braking power and control. By selecting a lower gear, you should be able to avoid using your brakes too much. Excessive braking on hills can result in ‘brake fade’ and loss of control. Brake fade is a loss of braking power caused by the heat generated by continuous use of the brakes.

Look for ‘escape lanes’, which are designed to stop runaway vehicles.

Overtaking

It’s only safe to overtake downhill where

• there are no bends or junctions
• your view of the road ahead is clear.

You should be absolutely certain that you can overtake without causing oncoming traffic to slow down or change course.

Remember that the vehicle you’re overtaking may build up speed, and you’ll find it more difficult to slow down for oncoming traffic. They’ll find it more difficult to get out of your way.

Look out for road markings, especially continuous white lines along the centre of the road.

Hills in towns

Take particular care in towns, where pedestrians may be crossing at junctions on hills.

Traffic speeds are generally lower and vehicles closer together. As a result, your view will often be reduced.

Pay attention to your distance from the vehicle ahead.

You’ll find traffic lights, school crossing patrols and pedestrian crossings are sometimes situated on a hill. Where this is the case, it adds to the importance of

• using your mirrors
• leaving a suitable gap when you stop
• using your parking brake effectively
• making sure you’re in the right gear for the situation.

You’ll be doing these things in towns already, but on hills they have additional importance.