I’ve arrived in Boston, from whence Route 95 goes all the way south to Miami and Route 90 goes all the way west to Seattle. The opposite corner of the country is Los Angeles, where Route 5 meets Route 10. The USA has this wonderful concept of interstate highways, multiples of 10 east-west and odd multiples of 5 north-south.

So I propose The Interstate Game. I tell you two numbers, and you tell me, what city lies at their intersection? For example: 25+70? 35+80? (Denver, Des Moines.)

Well, reality is a bit of a mess. Some of these highways barely cross a state, let alone a nation, and all told it seems around 47 of the 90 possible intersections actually exist. You also get plenty of oddities where two roads meet that shouldn’t according to Euclid — like San Diego at the intersection of 5 and 15. In fact in Dallas, three roads meet — 20, 30, and 45.

Still, we have plenty of fine cities to play with. And of course, you can run the game equally in reverse. Baltimore? That’s 95+70. Butte, Montana? 15+90. But who ever heard of Sulphurdale? (It’s near Cove Fort.)

[17 September 2023]