Preston's changed a lot over the years and becoming quite trendy so there's lots of activity around. South of Bell (The side you're on) seems to be safer as it's closer to the Thornbury side which is lovely. I've been in the area for quite a while, but as house prices increase, the 'shady' folk tend to move further out and the professionals and families move in. It's a great area to be in.
I actually live pretty close to Bell City myself. Look of the evening you can get some shady people walking the streets. As long as you stick to main roads and well lit streets while walking home you will be fine. Carry a whistle and some pepper spray just in case (: