Is the 20mph Limit the Answer to Safer Roads?
If you think you’re seeing more 20mph speed limit signs, you’re not imagining things. In London, 20mph limits have been in force in some areas since March 2020, with more than half of the capital’s roads now limited to the speed. Since the Welsh government imposed the limit on all of the country’s roads in residential and built-up areas in September 2023, many councils across the UK have followed suit or intend to, among the latest being Dorset and Surrey. What’s going on? Does a 20mph limit reduce accident and casualty rates or is it just an attack on motorists? Read on…
Who sets 20mph limits and how are they decided?
Traffic authorities, not the government, set local speed limits. Regarding 20mph limits, the government says authorities should only introduce them in the right places, over time and that they should be in urban areas and built-up streets that are primarily residential. Crucially, the new limit must have local support.
What’s wrong with 30mph?
At least if drivers obey the limit, not so much. The problem is that many regard a speed limit as a target figure, one they can exceed by a few miles per hour. It follows, then, that by lowering the limit you lower the average speed drivers are comfortable exceeding it by. This argument is borne out by Transport for Wales which found that after measuring the speeds of 3.4 million cars across nine locations over two weeks, average speeds on the country’s new 20mph roads had fallen from 28.9mph before the rollout to 24.8mph after it. Meanwhile, Bristol City Council has found that a 20mph limit encourages better compliance on 30mph roads.
What are the benefits of a lower speed?
Chiefly, a reduction in braking distance and impact forces. For example, from 20mph the average family car stops in just over half the distance that one doing 30mph takes – 12 metres compared with 23. On urban roads with low average traffic speeds, any 1mph reduction in average speed can reduce the collision frequency by around 6%. There is also evidence confirming the greater chance of survival of pedestrians in collisions at lower speeds.
How much have accident rates fallen on 20mph roads?
The Welsh government says that in the six months following the introduction of the new 20mph limit, the number of serious road casualties fell 17% compared with the same period the year before. Police forces in Wales said the statistics proved the new limit was working. According to TfL, 20mph speed limits have seen collisions fall by 25% and those resulting in death or serious injury, by 24%. For accidents involving pedestrians just crossing the road, it claims to have recorded falls of up to 60%.
Are 20mph limits popular?
Before the introduction of Wales’ 20mph limit, 80% of adults supported the change. However, after the limit was in place, a YouGov poll found that 70% of drivers opposed it compared with just 24% of people who approved it. Following a public backlash, in September 2024, the Welsh government began changing some 20mph roads in built-up areas back to 30mph and asked locals to tell their councils where other 20mph limits should be reviewed. However, it said it still believed in the new limits near schools and hospitals and in built-up residential areas.
Do drivers obey a 20mph limit?
The RAC says that it supports 20mph in areas with a high number of pedestrians and cyclists but that on roads better suited to 30mph there is a risk that drivers will ignore a 20mph limit. A spokesman said, “Among those who admit to speeding on 20mph roads, RAC research shows half of drivers say they do so because they feel the limit is inappropriate. This compares to just 28% of drivers who say they exceed the 30mph limit for the same reason.” The YouGov poll found that 40% of drivers admitting to breaking Wales’ 20mph limit had a limited belief that it had delivered its supposed improvements.
What’s the penalty for exceeding a 20mph speed limit?
First offenders only breaking the limit by a moderate amount can expect a £100 fixed penalty and three points or be offered a speed awareness course. Repeat offenders driving at excessive speeds may be fined a percentage of their income, decided in court. In July it was reported that drivers in Wales had been fined a total of £1.28m for breaking the 20mph speed limit, driving at average speeds of 28mph. One driver was caught doing 82mph.
Roughly how much does it cost to change a speed limit to 20mph?
Wales’ scheme has cost £34 million plus a further £5m given by the government to councils to reassess the new limit, a cost it said was outweighed by the reduced impact on the NHS and emergency services. Generally speaking, in the UK a 20mph entry sign and an exit sign each cost around £800 to purchase and install or £1,400 if illuminated. Repeater signs each cost around £300.
Following a FOI request in 2018, Hampshire County Council revealed that 22, 20mph signs and additional columns on one stretch of road cost £7,000 plus £7,481 for the painting of 95, 20mph signs on the road surface. The cost to revoke a 20mph limit, it said, would be £5,000. In 2023, Oxfordshire County Council set aside £8m to change speed limits.
What other speed limits may fall?
The Scottish government says it is consulting on plans to cut the 60mph limit on single carriageways to only 50mph in a move it said would result in a ‘significant reduction’ in road casualties. It has already unveiled plans to reduce the speed limit on most urban roads to 20mph by the end of 2025.
More than 2,000 people were killed or seriously injured on Scotland’s roads in 2023, while so far in 2024, fatalities are 26% higher than at the same time last year. The increase has been partly blamed on the fall in police officer numbers, leading to a ‘lack of visible presence’ on the roads. However, opposition politicians say the reduction in the speed limit to 50mph will encourage drivers to overtake slower vehicles, raising the risk of more accidents.
