5 February 2026
Drivers are overestimating their braking distances according to new research from The AA's Accident Assist team. When more than 10,000 drivers were asked the thinking distance for cars travelling at 20 mph, the average response was 19 metres, more than double the guidance in the Highway Code (12 metres). Similarly, drivers thought the braking distance at 20 mph was 25 metres compared to six metres outlined within the Highway Code. Drivers felt the total braking distance at 20 mph was 44 metres, almost three times the distance suggested in the Highway Code (12 metres).
In most cases, drivers felt the distances were greater than the Highway Code, with the exception of 70 mph. At this speed, they underestimated the physical braking distance by 3 metres (72 m compared to 75 m) but more than doubled the thinking distance (48 m compared to 21 m). The total distance exceeded the advice by 24 metres (120 m compared to 96 m).
How are stopping distances calculated?
Stopping distances are calculated by combining 'thinking distance' and 'braking distance'.Thinking distance is the length the vehicles travels whilst the driver reacts, and braking distance is the length the vehicle travels whilst braking.
The cumulative length of these two factors determines the total stopping distance.
The research comes as a third of drivers are unaware of or ignore the 'two-second' gap rule. Even government figures show that a quarter of drivers are too close to the vehicle in front**. One reason why drivers may believe that the thinking distance is greater is due to an increase in distractions such as someone using a hand-held mobile phone, playing with the infotainment system or passengers causing distractions in the car.
Q. The third edition of The Highway Code, released in 1946, first mentioned stopping distances. According to the latest edition (2025), what are the typical stopping distances for the following speeds? For reference, the average car length is 4 metres (13 feet). 10,030 respondents
| Driver mean speed | Thinking distance | Braking distance | Total distance |
|---|---|---|---|
| 20 mph | 19 m | 25 m | 44 m |
| 30 mph | 25 m | 34 m | 59 m |
| 40 mph | 31 m | 44 m | 75 m |
| 50 mph | 37 m | 53 m | 90 m |
| 60 mph | 43 m | 62 m | 105 m |
| 70 mph | 48 m | 72 m | 120 m |
Typical stopping distances were first introduced to the Highway Code in 1946. In the 1959 edition, the stopping distances for 20-60 mph were published with 70 mph added in the 1965 edition. Since these editions, the typical stopping distances have remained the same.
Typical stopping distances according to the Highway Code
| HC typical distance | Thinking distance | Braking distance | Total distance |
|---|---|---|---|
| 20 mph | 6 m | 6 m | 12 m |
| 30 mph | 9 m | 14 m | 23 m |
| 40 mph | 12 m | 24 m | 36 m |
| 50 mph | 15 m | 38 m | 53 m |
| 60 mph | 18 m | 55 m | 73 m |
| 70 mph | 21 m | 75 m | 96 m |
Drivers think update is needed
The AA Accident Assist team also discovered that three quarters (75%) of respondents felt that the typical stopping distances in the Highway Code should be revised to reflect modern vehicle technology and braking capabilities, but also to consider in-car distractions which may affect the reactions of the driver. Nine out of 10 (90%) drivers aged 18-24 felt that the Code needed updating in this area, compared to 77% of drivers aged 75 and older.
Tim Rankin, managing director of AA Accident Assist, said; "Considering the advancement of brakes, it is somewhat surprising that drivers overestimated the typical stopping distance of a car. Interestingly, people believe it takes longer to consider the surroundings and react accordingly than the Highway Code suggests.
"This only highlights the need for drivers to leave more room between themselves and the vehicle in front. While there is a good chance the brakes will bring the car to a stop, you are relying on the attentiveness of the driver to react in time. As well as leaving as much space as possible, staying alert, keeping your hands on the wheel and your eyes on the road are key to avoiding a crash. Around two fifths of crashes we attended last year involved a vehicle hitting another in moving traffic***.
"It is in everyone's interest to reduce incidents on the road. Any reduction in the number of collisions not only saves lives but also reduces costs to the NHS and would see insurance premiums come down for everyone as claims numbers fall."
* Yonder received 10,030 responses from AA members to its online poll between the 10th to 19th November 2025 Yonder is a member of the British Polling Council and abides by its rules.
** Vehicle speed compliance statistics for Great Britain: 2024 - GOV.UK
*** AA Accident Assist Reveals What Drivers Crashed Into During 2025 | AA