Combine this with a long-stagnant minimum wage and societal factors (we're slowly going the way of countries in Europe and the Middle East with high youth unemployment and ever-extending quasi-adult periods), it should keep going down in younger drivers. Outside of North America it isn't uncommon to encounter people well into their 30s or beyond that never learned to drive.
When and where I started driving, gas was often below $1 in the late 90s. With today's average prices they'd need to make $15 an hour and get their cars for half the price (the inflation in used car prices is absolutely staggering, many don't even lose a quarter of their value in 5 years, whereas at the time you could get them for less than half their new price, and it went down even more for older cars). There is no denying that the barrier to entry is far higher today.
Personally, I drive less than I did from my teens through my mid-20s because I can now control where I live, refuse to live far from work, and hate traffic. However, I drive more now than I did last year because I moved to a more isolated semi-rural area that allows me to endure less traffic outside of commuting. In all, the miles traveled in my household are down in spite of this, simply because we no longer do the extreme commutes that were necessary in SoCal.