There’s some possibly surprising news that the extended opening hours following the 2003 Licensing Act have actually led to a reduction in drink-drive casualties amongst younger people, particularly at weekends. At first sight this may seem counter-intuitive, and before the legislation was implemented there were widespread predictions from an unholy alliance of the anti-drink and anti-car lobbies (between whom there is a substantial overlap) that it would lead to an explosion in drink-driving, especially as it would mean pubs routinely staying open after public transport had stopped running.
The mechanism behind this isn’t immediately obvious, but it seems in general terms that the relaxation of closing times has led to a less frantic and pressured approach to drinking and encouraged people to pace themselves more. It could also mean that we’re not putting all the drink-drivers on the road at the same time so they’re less likely to crash into each other, but I don’t really think it quite works like that. One very noticeable effect is that staggered closing times have removed the previous spike in demand for taxis at around 11.30, which might make people more willing to trust to that form of transport.
While there may be recent research that I’m not aware of, I get the impression that the motivations leading people to become drink-drive offenders are not very well understood and this hinders the development of official policies to combat it. The traditional stereotype of middle-aged, middle-class blokes knocking it back in country pubs and golf clubs was never more than a small part of the problem and becomes less and less relevant as the years go by.