Stopping Distances UK: Highway Code Chart and How to Remember It

According to The Highway Code, typical stopping distances on a dry road are 12 metres at 20 mph, 23 metres at 30 mph, 36 metres at 40 mph, 53 metres at 50 mph, 73 metres at 60 mph and 96 metres at 70 mph. Each figure is thinking distance plus braking distance. In the wet, stopping distances are at least double, and on ice they can be up to ten times longer.

These numbers come up in the theory test, but more importantly they show why speed and following distance matter so much.

Highway Code typical stopping distances chart

These are typical figures for a well-maintained car with an alert driver on a dry road. Real distances can be much longer.

Thinking distance vs braking distance

• Thinking distance is how far the car travels while you notice a hazard and move your foot to the brake. It grows in step with speed, which is why it goes up by 3 metres for every 10 mph in the chart.
• Braking distance is how far the car travels once the brakes are applied. It grows much faster than speed. Going from 30 to 60 mph doubles your speed but nearly quadruples your braking distance (14 m to 55 m).

Road safety charity Brake points out that the Highway Code's thinking distances assume a fast reaction and that real-world reaction times are often longer, especially if you're tired or distracted.

What makes stopping distances longer

• Wet roads: at least double (Highway Code rule 227).
• Ice and snow: up to ten times longer (rule 230).
• Worn tyres or incorrect tyre pressures.
• Worn brakes or shock absorbers.
• Going downhill or carrying a heavy load.
• Tiredness, distraction, alcohol or drugs, which all slow your reactions.

The two-second rule

You can't measure metres while driving, so the Highway Code (rule 126) gives a time-based gap instead: leave at least a two-second gap behind the vehicle in front on roads carrying fast traffic and in tunnels where visibility is reduced. The gap should be at least doubled on wet roads and increased up to ten times on icy roads.

How to check it:

1. Watch the vehicle in front pass a fixed point, such as a lamp post or bridge.
2. Say "only a fool breaks the two-second rule" at a normal pace.
3. If you reach the point before you finish, drop back.

In slow town traffic, a smaller gap is normal, but always leave enough room to stop safely.

Easy ways to remember the chart for the theory test

1. Thinking distance: start at 6 m for 20 mph and add 3 m for every 10 mph (6, 9, 12, 15, 18, 21).
2. Total distance: a popular trick is to multiply the speed by a rising factor: 20 × 2, 30 × 2.5, 40 × 3, 50 × 3.5, 60 × 4, 70 × 4.5 gives the total in feet (40, 75, 120, 175, 240, 315). It's very close to the official figures; note the official figure at 40 mph is 118 ft.
3. Braking distance: subtract the thinking distance from the total.

Revise this together with UK speed limits for the theory test. Our theory test revision plan suggests making a one-page "numbers sheet".

Summary

At 30 mph you need about 23 metres to stop; at 70 mph, about 96 metres, and that's on a dry road. Double it in the wet, multiply it up to ten times on ice, and keep at least a two-second gap on faster roads. Leaving space is the simplest form of defensive driving, and it matters even more in rain, fog and snow.

Revise with Co-Drive

Co-Drive is an iOS app with original theory practice questions written from The Highway Code (not official DVSA questions), including stopping distances and speed limits, with spaced review to help the numbers stick. Try Co-Drive.