I can't drive because of an eye condition. Honestly, this has been a bane of my existence for most of my (adult) life. In Australia a non-car lifestyle is possible but very limiting. You have to pick and choose where you live and figure out how to get to and from places.
In Europe the situation is much better overall. In London you don't need a car but it's still awkward if you need to go home after midnight. The Tube stops. Cabs are crazy expensive. The night bus is a freak show. Going out of London is a problem and expensive.
Switzerland on the other hand was (mostly) amazing from a walker's perspective. Living in a rural town sans car might be problematic but you can get pretty much anywhere in the country by clean, reliable trains. I lived in Zurich and got to all sorts of places are Lake Zurich and Lake Luzern for hiking and the like.
I now live in New York City. I have visited a number of parts of the US. In most of the US you are utterly dependent on the automobile in a way that residents of other industrialized nations probably can't quite comprehend.
I've stayed with friends in the Midwest who parked their car 8 feet from the front door of the their condo, drove to work where their car was pretty close to the office and often got food through drive throughs. They'd probably walk less than 500 yards a day.
Most places in the US aren't just pro-automobile, they're anti-pedestrian and anti-cyclist. Things like:
- Limited to no public transport
- Public transport that becomes unusable at certain hours
- Light changes at intersections that may stop a pedestrian for as much as 5 minutes
- Allowing cars to turn right at red lights. This is perhaps the most anti-pedestrian/cyclist law of all. The number of times I've been almost wiped out in this situation is insane.
- Low density housing.
Even some more pedestrian-friendly places like San Francisco still kinda suck (but SF is a lot better than anywhere else in the Bay Area).
NYC is a bit of a pedestrian mecca. As someone who can't drive, I've never quite had the independence and freedom I have right now by living in NYC. Reasons include:
- Pedestrian-friendly light changes (you never have to wait more than about 30-45 seconds for a light change)
- Subway that runs 24x7 and frequently
- Cheap cabs
- No turning right at red lights. Some visitors to NYC don't realize this is illegal in the five boroughs.
So now I live walking distance to work. The downside is that being able to do so is expensive as a single person and the domain of the wealthy for those with more than 1-2 kids.
The thing that really boggles my mind is how blase we as a society are to the 30,000+ people who die every year in the US in motor vehicle accidents [1].
This is the same number of fatalities as 10 9/11 attacks every year. The cult of the automobile simply defies reason.
There are a couple of points worth making about walking as exercise:
1. Some is far, far better than none. You need some exercise simply for proper functioning of your body; and
2. Walking, and exercise in general, is not the primary solution to obesity. According to a calculator, a 200 lb man burns 120 calories by walking 1 mile in 20 minutes. Not a brisk pace at all. A 12oz can of soda has ~140 calories in it.
Now the relationship between calorific intake and weight gain or loss is complex and somewhat controversial in some circles but, generally speaking, if you consume more calories than you burn you will tend to gain weight and if you consume less than you burn you will tend to lose weight. The body makes some effort to maintain homeostasis so minor changes may result in no change at all.
Exercise certainly helps but diet tends to be the far bigger problem.
[1]: http://en.wikipedia.org/wiki/List_of_motor_vehicle_deaths_in...