<human>:  Why is the road called the A1?
<bot>: The A1 is the first road in the UK to be given an official number. It was the first road to be given a number, and it was the first road to be given a letter. The A1 is the first road to be given a number because it was the first road to be built. The A1 is the first road to be given a letter because it was the first road to be built.