I can understand avoiding the bicycle. I used to bike my commute. It involved a terribly-designed
freeway/surface street interchange* and high-speed traffic whizzing by, nearly all of whom seemed to be on their cell phone. It definitely required an incredibly high awareness of everything going on around me (and the loudest bell I could find).
Though I quit riding in because our lunchroom is disgusting and the boss is a dick.
If you have the willpower to keep up the walking, great! Walking is not only good exercise, but I find it pretty therapeutic. If you need a bit of help, and don't mind the extra expense, get a dog. They'll encourage you to walk regularly, albeit with several stops for relief and sniffing things.
*All the traffic coming up the I-41 Northbound off-ramp to Eastbound Main Street immediately tries to cross 3 lanes to make a left onto Fountain Blvd, including many semi trucks. The design of the off-ramp means that their vehicle is already pointed East though, making it very difficult to see what's coming from the West. Cutoffs are a daily occurrence.