These are rare in the UK, but they do exist in places where going too slowly can cause congestion or high risk of an incident, such as in tunnels. They’re marked by a blue circular sign containing the minimum speed limit. At the end of a minimum speed limit you will see the same sign with a red line through it. Although there isn’t an official minimum speed limit on most motorways, travelling too slowly is considered dangerous. In the eyes of the law driving too slowly is deemed ‘careless driving’ and a hazard to those who are following the speed limit maximum and could be prompted into reckless overtaking. As a rule of thumb, you should use the maximum speed limits as a guideline. If you don’t stray too far below this, you won’t put others at risk or break the law.