Mouth ulcers are also a possible symptom of a viral infection that mainly affects young children, called hand, foot and mouth disease. Speak to your GP or call NHS 111 if you're unsure. Read about the symptoms of hand, foot and mouth disease.
It was not until 1965 that a national upper limit of 70mph was introduced for all roads, including motorways. Since 1977 the speed limit for cars and motorcycles on dual carriageways has been 70mph, with a 60mph speed limit on single carriageways.
However, the posted minimum speed on these systems did not change. In fact, the survey showed that 14 states still use 40 mph minimum speed limit signs, 10 states use 45 mph, and 1 state uses 55 mph. Furthermore, the survey showed that 25 states do not post minimum speed limit signs.