This map shows the shortest pub crawl that’ll take you through every pub in the UK
Scientists working in Canada have tackled the question that’s been on the lips of every thirsty drinker – how long would the pub crawl be if you visited every pub in the UK?
The map is a thing of wonder:
And answer is…. 45,495,239 meters or just over 28,000 miles.
And if you did this pub crawl at 10 miles walking a day – it would take you 7.7 years.
7.7 GLORIOUS years.
And here’s how these men of science worked it all out:
Nearly everyone in the UK knows by heart the best path to take them over to their favorite public house. But what about jotting down the shortest route to visit every pub in the country and return home safely? That is what we set out to do.
Okay, maybe every pub is overstating the goal. Pubs in the UK are closing shop or starting up, fresh and new, all of the time. Any route would be out-of-date by the time it was created. So we set a more modest goal: find the shortest route to visit some 24,727 stops found on the great Web site Pubs Galore – The UK Pub Guide.
This is a concrete target. But still an overstatement. Only a real local could possibly know every shortcut, slipping between buildings and along dark allies, to find the absolute best way to reach The Fiddler’s Elbow or The Bald Faced Stag. This is well out of reach for a humble team of mathematicians.
Here we rely on the fantastic service provided by Google Maps. Ask Google for the shortest way to walk from The Elbow over to The Stag and it will respond with excellent step-by-step directions. The level of detail covered by Google Maps is amazing.
So this is our challenge. Using geographic coordinates of 24,727 pubs provided by Pubs Galore and measuring the distance between any two pubs as the length of the route produced by Google Maps, what is the shortest possible tour that visits all 24,727 and returns to the starting point?
Well, almost. We need to make one final assumption. It sounds like something only a mathematician would consider, but we have to assume that the route Google suggests for walking between The Fiddler’s Elbow and The Bald Faced Stag is no shorter than the route a smart crow would fly. This makes it conceivable to solve the problem without actually asking Google for the distance to travel between each pair of pubs, an important consideration since there are 305,699,901 pairs and Google puts a cap of 2,500 distance requests per day.
This is the problem we have solved. The optimal tour has length 45,495,239 meters. To be clear, our main result is that there simply does not exist any pub tour that is even one meter shorter (measuring the length using the distances we obtained from Google) than the one produced by our computation. It is the solution to a 24,727-city traveling salesman problem (TSP).
