Reading Bill Bryson’s At Home, a big, genial shaggy dog of a book brimming with turn-to-the-wife-did-you-know-that moments (in other words, absolutely recommended), I came across this interesting traffic note, about the blackouts introduced to Britain at the outbreak of the war:

Drivers had to drive around in almost perfect invisibility—even dashboard lights were not allowed— so they had to guess not only where the road was but at what speed they were moving.

Not since the Middle Ages had Britain been so dark, and the consequences were noisy and profound. To avoid striking the curb or anything parked along it, cars took to straddling the middle white lines, which was fine until they encountered another vehicle doing likewise from the opposite direction. Pedestrians found themselves in constant peril as every sidewalk became an obstacle course of unseen lampposts, trees, and street furniture. Trams, known with respect as the ‘silent peril,’ were especially unnerving. ‘During the first four months of the war,’ Juliet Gardiner relates in Wartime, ‘a total of 4,133 people were killed on Britain’s roads’—a 100 percent increase over the year before. Nearly three-quarters of the victims were pedestrians. Without dropping a single bomb, the Lutwaffe was already killing six hundred people a month, as the British Medical Journal drily observed.