Lack of sidewalks a contributing factor?

After moving here I've decided that sidewalks (or lack thereof) can be a huge factor in inactivity that leads to being overweight. I just searched online and found that it can be a contribution to obesity. Sidewalklessness is an odd phenomenon that I've not experienced anywhere else. However, sidewalks are not common here. They will end in the middle of the block if the housing ends in the middle of a block. I've felt quite constricted and confined to the housing developments with which we are clustered. After that it is "un-sidewalked territory" and it's rather frightening to try and run on the street.

Picture University Ave. in Provo with no sidewalks. That's what it's like on our University Ave. here except here it's larger and busier. It's the very busy 4 lane road that runs in front of our neighborhood. It connects our portion of the city to the shops and grocery stores. I would probably walk there every other day (just so I can get out and about) if there were sidewalks. But no, they've neglected to connect us with the others.

As I'm looking for work it's frustrating to google the location and see that it's less than 3 miles from my house, but not very accessible to me without a car. I'd ride a bike, but that's almost unheard of here, and I don't know if cars would know what to do on a busy street with a cyclist.