We scrutinised 11 million car insurance quotes run on our site in the 12 months to September 30 to identify the biggest offending postcodes for driving under the influence.
Crewe (postcode CW) took first place, having logged 1.74 drink or drug-driving convictions per 1,000 drivers.
The next four slots in the top five are occupied by Welsh postcodes – Llandrindod Wells (LD – 1.60 per 1,000 drivers), Cardiff (CF – 1.59), Newport (NP – 1.58) and Swansea (SA – 1.58).
At the other end of the scale, the three postcodes with the lowest number of convictions per 1,000 drivers are in London (WC, NW, and E). London WC had a conviction rate of just 0.12 per 1,000 drivers, with NW at 0.66 and E at 0.68.
The other two postcodes in the bottom five are Bradford (BD – 0.68) in Yorkshire and Ilford (IG – 0.76) in Essex.
The good news is that the overall number of convictions for drink and drug-driving appears to be in decline.
The highest rate of offences when we ran these numbers last year was 1.98 per 1,000 drivers – this was in the Llandrindod Wells postcode. That means we’ve seen a drop of some 12% in the 12 months to October 2015.
Similarly, the lowest rate of convictions in 2014 was 0.76 in the London E postcode, but this tumbled to 0.12 in London WC this year.
While this is encouraging, drink and drug-driving remains a significant problem on UK roads, with an estimated 100,000 convictions every year. According to the Department for Transport, drink-driving incidents are responsible for around 500 deaths and 2,500 serious injuries every year.
The peak time for drink-driving is the summer, reflecting the fact more people drive to pubs in the evenings. But, perhaps inevitably, there is another spike in the weeks running up to Christmas and New Year.