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.
States had the power to establish their own speed limits until 1973, when Congress enacted the first national speed limit of 55 mph. This was partly aimed at limiting Americans' gas guzzling in the face of an oil shortage.