Quite bizzarly I have had around 7 or 8 punctures on my commute since I started 18+ months ago and of the ones that were flat during the trip (not the flat when returning to the bike after the trip variety) they have without fail occurred at or approaching the
Morrisons at Bredbury so I have always limped onto the petrol station forecourt and fixed them in a sheltered, well lit corner. This is also, give or take 1/2 mile, the midpoint of my 10 mile commute. The last time this happened I could hear the front tyre hissing as I climbed the hill towards Morrisons so decided to keep going to my 'usual' spot but by the time I had fixed the front the rear was also flat, also with a tiny shard of glass just like the front. Thankfully I had 2 tubes with me and felt vindicated for doing so!!!