Looks good, if a little visually odd with the plain white table.
I'll second Oscar's point about '0'. There are legit route zeros in
Belgium,
Czechia and
Hungary. The others are unnumbered and ought to be listed at the bottom of the table (if at all?) under '-' or some other N/A descriptor.
There's also some false positives where a named road has a number in it, like
T5 Spur (the spur of the motorway network to Heathrow Terminal 5), or
MKAD2 (the 2nd Minsk Motorway Ring)
My score of 69 is surprisingly good, looking at that thread and seeing how low ranked, generally, I am in travels. It's also quite nice to be able to see the highest number I've travelled on (8008 - my travels seem to be rather childishly dirty!).
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"TM is chock full of toys for subsets of the userbase!"
Are there toys for other similar games that use our database and user data that could also be implemented?
How about a stat for how many unique numbers has someone travelled on? (and in a 4-digit only variant, I think I might win - certainly top 5. Thanks GB numbering scheme!) Could be put on the same page as it is a similar game.
There's also how many different prefixes you've done (not the same as how many systems as many systems share prefixes like A, B, N or D, and others have several prefixes, like in Spain), but that might be a bit harder to implement.
And then there's the "have I done every route with that number game". It's a little meaningless with higher numbers that are likely to be unique, and with the global nature of the TM database would be rather impossible, but filters and the like to get it down to something meaningful allowing you to say something along the lines of "hey, I've done part of every route 1 in the US and Canada" sounds like a fun game.
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There's the general geekery stuff that doesn't use user data - roads of same numbers but different type meeting each other (excluding banners), concurrency stats (longest, most), nodes with the most branches out of them, what numbers don't have roads attached to them?, etc. Would pages for them be a good idea?