Maths professor works out the ultimate, 28,000-mile pub crawl

MATHEMATICIANS have worked out the ultimate British pub crawl with the shortest distance needed to visit almost 25,000 UK hostelries.

However, it may take a little time to get round all the 24,727 watering holes listed on the Pubs Galore website, as the route is – at 28,270 miles – longer than circumnavigating the globe, said the professor who produced it. It has broken the record for being the longest single road route ever calculated, said the international team of researchers behind the analysis.

To calculate the shortest route needed to go to every site on Pubs Galore, the team led by William Cook, a maths professor, fed into computers the distance between 305,000 pairs of pubs. These were worked out using Google maps in a process that took more than two years from start to finish, said Professor Cook of the University of Waterloo in Canada. The problem he was try- ing to solve is known as the Travelling Salesman Problem (TSP) – the logistics of working out the shortest possible routes for salesmen covering a large patch in the US.

But the pub route had at least 100 times more stops than any previous TSP that had been worked out, said Prof Cook, an expert in TSPs. He said: “We, of course, did not have in mind to bring everything mathematics has to bear in order to improve the lot of a wandering pub aficionado.

“Rather, we use the UK pubs problem as a means for developing and testing general-purpose optimisation methods, which have wide applications in science, industry and commerce. The TSP itself is used to route the trucks that bring packages to your door, to compute DNA sequences in genetics, to aim telescopes, to schedule production runs in factories, to design circuits on computer chips, and on and on.”