Tuesday, 30 January 2018

One, Two, a One Two Three Four

I've recently been educated about three numbering systems that make more sense than I ever knew.

Lots of Ferraris have a number as part of their name and it does actually mean something. It's the capacity of each cylinder in cc's. So a 250-GTO is a car where each cylinder is 250cc. It's a 12 cylinder car (you're just expected to know that) so it's got a 3 litre engine.

In America the exit (junction) numbers on the interstates are monotonic but they are large and non-contiguous. It turns out that they're the number of miles from the start of the road. It's a brilliant system, they never put up distance signs, but every time you go past an exit you know how far it is until your exit. You can estimate distances quite accurately by just glancing at a road map. (Pass me my driving dividers).

The numbers of "A" and "B" roads in the UK also make more sense than I ever imagined. The country is divided into 6 sectors by 6 one-digit "A" roads which all go to London. They are the A1, A2, A3, A4, A5 and A6. Less important roads have 2 digits and then 3 digits. The first digit is the sector number. The roads are numbered by going round the whole country clockwise. You might be tempted to ask which end of the road gets the number. Does the A38 go from Cornwall to Nottinghamshire or Nottinghamshire to Cornwall. Clearly it's the former because all roads run clockwise around London and you leave London on your starboard side if you drive North on the A38.

I'm delighted to note that near where I live the A379 is south of the A38 and the A386 is generally north of it.

Richard "In and out of Wandsworth with the numbers on their names" B

No comments:

Post a comment