Driver's hours and HGV speed restrictions are why. This is a form of protest, likened to "working to rule". If an HGV driver does not reach his destination within his drivers hours he has to pull over and rest, wasting his time, losing income and depriving his family of his company. The answer is to abolish specific limits for HGVs. Some companies will still speed restrict their HGVs for reasons of fuel economy. Others will regard time as more important. But it will mean that faster trucks can overtake slower trucks, get out of your way and get your food to you while its still fresh.