They divide the population of the USA into four generations: Baby Boomers (anyone over 45); Generation X (35-45 years old); Generation Now (15-34) and Digital Natives (younger than 15). Whilst Baby Boomers and X-ers were in love with cars and got their licences young - in 1978, for instance, 75 per per cent of American seventeen-year-olds had theirs- Generation Now aren't quite so obsessed. In 2008, only 49 per cent of their age cohort had passed their driving test by the age of 17. If a machine does it for them, they won't care. They're happy to limit their driving experiences to Grand Theft Auto (p 322-323).
A similar generational divide is apparent in data shown in The Economist (right graphic, below). It is the old question: is new tech a good or a bad substitute for old tech? The nature of substitutes is always in the eyes of the beholder. Beholders of different ages come at this is different ways - and entirely as we might expect.