I think that the conclusions drawn from the data are a bit simple and seem to have a 'leaning' to them. For example: reallocating resources away from car infrastructure (parking, residential parking capacity (zoning minimum parking), roadway repairs and upgrades, new arteries and optimized urban routes) to collective transportation systems is a blunt, big picture approach that we need to stop using. Saying that less people are using cars means we need to shift away from their support is like saying more people are becoming obese and eating poorly, we need to shift toward a pro-fast food culture. We need to shift towards people's 'productive' wants and needs, not their possibly desired or desperate short or long term behaviour trends. We need to be more sophisticated than that. Much (but not all) of the data suggests that cars are a very important part of people's weekly if not everyday lives and we need to accept a multi-modal investment. What the data never seems to suggest is the increased productivity, wealth-generation, and economic growth potential of car users, car infrastructure, and a lifestyle which includes cars. These studies always seem to neglect personal and society-level economics and prosperity in their research. The ideal case is for everyone to purchase, maintain, and park a car but reduce use for everyday, regular commuting, and single-occupant purposes. The bottom line is that a family (however you define that, 1-7+ persons) is almost always more productive, flexible, and versatile with a car that is owned and immediately available, which usually translates to increased worth, quality of life, and self-actualization. The economy directly benefits and therefore can increase outlays to less productive (but vital) elements - environment, health, and social well-being. There doesn't seem to be any evidence that a highly-focussed transit culture increases overall incomes, job opportunities, consumption, technology take-up, overnight social events, away-from-home vacationing, home ownership, or other elements that many economists identify with a growing economy. All urban (non-rural) centres should have local and commuter, widespread, high-speed, high capacity, 24-7 transit systems, but ironically that is often only facilitated by a large tax base and moderate to high income residents, which is primarily made-up of highly educated, mobile, and productive citizens - almost exclusively those who have (but may not always use) cars. Need more transit? Don't neglect car culture and the wealthy taxpayers who are a vital component of that group - funny how it works that way.

The real reasons for less miles driven (per capita) in many areas of USA is so evident that it is not even mentioned.

As 97% are relatively poorer and many more were unemployed and gas cost a lot more, the majority cannot afford to drive as much as they did in 2004.

Poorer people have no choice but to drive less and less, use lower cost public transport, share cars, use bikes or walk more.

With employment gaining speed (under 7% unemployed for the first time in 5 years or so), Americans will start (in 2014) buying more cars and drive more. However, the relative riches is getting worst month after month. Eventually, more and more Americans may have to walk or use public transport.

@HarveyD

I am probably wasting my time typing this as you seem to ignore most facts but Bob Wallace's comment is much more to the point. I know first hand from having a son that was much more interested in other technology. He has a car and drives but owning a vehicle was not a priority.

When I moved to Utah 30 years ago, there were very few bicyclists. Now it is commonplace and we now have many streets with bicycle lanes. we also have more public transit including commuter rail. Anyway, I would be much more inclined to believe that it is a cultural change rather than an economic necessity.

Another major reason why the per capita miles travelled is going down may be demographics.

In many places, the percentage of retired older people is going up rapidly. Retired people use their private car a lot (-30% to -50%) less and often use one car instead of two. Many retired people stop driving in the last 5 to 8 years of their medically extended life.

This is anecdotal but I suspect it has some validity.

I'm a year or two older than the boomers. When I was young (and the boomers young) the US was much more a rural nation along with a lot of people living in small towns. Cars meant freedom. Freedom to get away from ones house and spend time with friends.

We worked and scraped to be able to afford some sort of car and we spent a good deal of time patching up the junkers we could afford. It was that, or stay home.

Now we're an urban/suburban nation. Friends are in easy walk/bike/skateboard distance.

I still live a (very) rural life. My lifestyle would be impossible without a car. But when I'm in Europe, Asia or South America where interesting things are close by and public transportation readily available I never rent a car. Why would one want to pay the extra, deal with traffic and finding ones way around, and looking for parking places when you can hop on the bus/train/Metro?

"You have to be an idiot to believe that a specific car will bring true happiness"

Ah, you never drove mountain roads in my RX-7. That was pure joy.

"I think this is aided by the fact that the younger generations actually are more intelligent than boomers or older people."

Our was a different world. We were wise enough to live before the planet got really crowded.

And we had really, really good music....

How about the idea that driving is no longer as much fun?

There used to be lots of uncrowded roads and no radar.

I'm not saying that driving fast was safe. I've lost friends along the way. But barreling down an empty road with the radio cranked up loud was something easier to do 'way back then'.

And, how about the idea that driving around America is not as interesting as it once was?

It's McTown after McTown.

Perhaps people are flying to resorts and more exotic destinations rather than putting a few thou on their cars taking road trips.

I'd guess there are a number of factors eating away at our driving totals.

I suspect we're going to see a decrease in the cost of owning and driving cars going forward.

I am assuming a ~200 mile range capacity EV battery.

If that happens then we should see the cost of cars dropping below that of ICEVs. Batteries, produced in huge numbers, should be cheaper than ICEs.

Cost per mile will drop significantly. Both fuel and maintenance.

Car lifespan will increase. A fresh not-expensive battery will turn a 120k, 150k EV into a fresh machine. As people buy new cars simply because they want a later model we will see more very usable used cars available for reasonable prices.

Fresh battery, "$99" paint job, set of seat covers/carpets and people with lower means should be able to buy reliable and quite serviceable vehicles.

We get self driving EVs and I suspect some people will move back off public transportation. If the time penalty is not extreme or if one can get work credit for in-car work.

Very recent stats confirmed that all four factors have gone up by about 4+%:

1. the economy
2. new car sales
3. number of jobs.
4. per capita miles travelled.

If the trend keeps on for 2 more quarters, one could say that a very close relationship exist between the four factors and that Americans will buy more cars and use them more if they work and can afford to do so.