Recently there has been a lot of chatter about how young people are trading cars for smart phones. Most of the evidence supporting such claims seems to be from this US PIRG report from the Spring. This Motor Trend article is representative of the press coverage. (When can we stop calling smart phones 'phones'? The telephone is perhaps the least useful feature for many. Will smart phone become a generic term like "Xerox"? See here and here about the death of phone calls.) One thing I don't like about the US PIRG report and subsequent coverage is that there is an assumption--sometimes explicitly stated--that people treat smart phones and cars as substitutes. I'm not sure this assumption is right, but certainly the car companies and Apple view smart phones as complements. See this NY Times story about smart phone integration with cars. Here is a story explaining that Apple just announced Siri will be a new car feature.
We certainly have to worry about distracted driving, but it seems more plausible to me that auto companies will integrate smart phone features into cars than the people will forego autos in order to use smart phones. The trends in auto ownership and usage are down for young Americans, but I'm not sure that the increase of smart phone ownership and use is the reason for this. It is also possible that by integrating smart phone applications into autos the auto experience is enhanced, leading to higher increasing utility from cars.