In 1933 road worker Percy Shaw was driving home over the hills from Bradford to Halifax. It was a foggy night and visibility was poor. Usually Percy was guided by the reflection of his headlights on the tram lines that ran the length of the road, but they had been taken up for repair. The night was dark, the fog was thick, and the road was treacherous. Suddenly Percy saw two pinpoint lights shining at him straight ahead. A cat, sat on a fence separating a bend in the road from a steep drop, had saved Percy from a potentially nasty accident. And the Cats Eye, the reflective sphere set into the middle of roads, was born.
Of course road safety pioneers have not been exclusively British. In 1917 June McCarroll, a doctor in Southern California, was run of the road by a ten ton truck barreling down the centre of the road. Incensed, she wrote to the local chamber of commerce and the county board of supervisors demanding that they put some sort of system in place to mark out separate lanes. When she had no luck going through the official channels she bought a can of white paint, got down on her hands and knees, and painted a line down the middle of the road herself. McCarroll continued to campaign, and by 1924 the idea was taken up by the California highway commission and pretty soon afterwards the rest of the world.
I was going to finish off with an explanation of why the British drive on the left, but Americanmum did a good job of this a couple of months ago.