Huge drop in casualties in 1st 6 months of 20mph in Wales

Data released by the Welsh Government on 31 July 2024 for the first six months of its 20mph national default speed limit on built-up roads shows 351 (29%) fewer casualties compared with the equivalent period last year (October to March). This follows on from the reported drop in speeds of 2 - 4mph. Having noticed lower vehicle damage claims, esure Group has now reduced insurance costs for drivers in Wales. Although two quarters of data are not definitive, the combination of lower speeds, fewer casualties and reduced vehicle damage claims, all indicate real benefits that are a trend and not a ‘blip’.

Wales set a default speed limit on built-up roads of 20mph on 17 September 2023. Lower mean speeds since then have led to 351 (29%) fewer casualties in the first six months (October to March)[1] compared with the previous year. Lower than expected vehicle damage claims has enabled esure Insurance Group to reduce its premiums for Welsh drivers.

Having reviewed 3 quarters of data, esure Group has seen a materially lower trend in accident frequencies in Wales. It has now formalised its approach and is committed to reducing policy prices for customers within 3 months of identifying a new 20mph area in the rest of the UK[2].

It’s still early days – six months of data is not definitive – but taken together with evidence from elsewhere, the following indicatex that the positive impact of 20mph in built up areas is a trend and not just a ‘blip’:

The drop in casualties on 30/30mph roads is greater than on roads with higher speed limits is smaller, where the drop is just 2% (Fig. 1)
The second quarter’s data[3] confirms the downward trend in casualties seen in the first quarter following implemention[4]. In Q4 2023 there were 32% fewer casualties on 20 / 30 mph roads than in Q4 2022. In Q1 2024, that difference was 26%.
The longer-term downward trend of reported casualties increased from September 2023 on 20/30mph roads (Fig. 2)
Although figures vary between individual Local Authorities (Fig. 3), some messages are consistent
1. 20 out of 22 LAs saw fewer casualties on 20 / 30mph roads (15 dropped by more than 20%)
2. On 40mph+ roads, 11 LAs had fewer casualties and 11 had more.
Casualty reductions of 29% are in line with those predicted by lower mean speeds (2.4mph[5] overall and 4.3mph on faster roads[6]).
Vehicle damage claims in Q4 2023 from esure are 20% lower than expected.[7]