Smart motorways, do they work?
The short answer, in my experience, no. That's not to say that I think “smart” or “managed” motorways are an inherently bad idea. The theory is sound and a study of a section of the M42 which was upgraded in 2006 showed that journey time savings of between 1 and 4 minutes could be achieved during rush hour. 1 minuted saved using variable speed limits alone and 4 minutes with variable speeds and opening of the hard shoulder. Highways England also say that “ personal injury accidents reduced by more than half ” and “ where accidents did occur, severity was much lower overall with zero fatalities and fewer seriously injured ”. So if the data suggests that smart motorways can reduce journey times and make motorways safer, why do I think that they do not work in practice? The main factor which I believe means they do not work to their full potential is the human factor. But I also believe there are other issues which hinder drivers and the ability for smart motorways to smooth traffic