This past weekend was always going to see a big influx of people into the capital for three of the year's major sporting events: the two FA Cup semi-finals and the London Marathon. And there are some things for which no one is to be blamed. It was no one's fault that the football brought to Wembley four teams from the North; no one's fault that a scrapyard fire broke out where it did, close to a key stretch of the M1, and no one's fault that the road had to be closed. Not every inconvenience can be put down to overzealous enforcement of "health and safety".
But the conjunction of circumstances that led to the complete closure of the M1 into and out of London serves to highlight some critical deficiencies in the infrastructure in one of the most densely populated parts of the country. That a fire could endanger a vital motorway to the extent that a bridge has to be built beneath it for reinforcement casts worrying doubt on its resilience to start with. That so many people drive into London shows up the continuing insufficiency of the rail network (especially at weekends), while the resulting traffic jams point to the inadequacy of alternative routes. If anyone doubted that our infrastructure is perilously overstretched, the sight of a car-less M1 between Brent Cross and Elstree supplied the proof.