Sometimes there's sidewalks, but often they're not continuous and just end for no apparent reason. You then have to walk in the road next to the cars for a ways and hope the sidewalk starts up again.
Even if there are sidewalks, there seems to be a unspoken "don't walk at night" rule even in safe neighborhoods. If I do walk at night, I get suspicious looks. Am I frightening the neighborhood by going on a walk after dark? It sure feels like it.
In suburbia, I'll even get suspicious looks walking during the day - as if I'm scoping out houses to rob or something. And I'm a pretty boring safe looking type of guy (so I'm told, haha).
The exception to this I've found is if I'm walking a dog or walking with another person (preferably female) to legitimize me as a walker.
The longer I'm in these parts of suburbia, the more I realize that these attitudes are somewhat justified. Sadly, I don't think I've ever seen a man walking around the neighborhoods by himself unless he was a vagrant.
Apparently the vast majority of men in these neighborhoods just don't ever go on walks unaccompanied. Otherwise it would turn into a 'normal' activity and the suspiciousness of it would subside.
I realize there are probably great neighborhoods in the US for walking, but from my limited experience (living in ~10 states), they seem pretty rare outside of urban centers.
I spent a lot of time in Germany (US military communities) growing up and it was a totally different experience. Much of Europe that I've seen is likewise a vastly better experience for walking.
In 6 days I'm moving to Berlin. Why? Well, I'm bootstrapping a small systems-training business and want to live somewhere low cost and without a car. While cheap walkable places surely must exist in the US, they're rare and I haven't been able to find many that are also safe and not run-down. If I'm missing some, please let me know!
After being in US suburbia for the last few months, I'm really looking forward to being a first-class citizen as a walker again.