Basenjis are sighthounds and will take off after things that move. They also are pretty good at picking up a scent and following it and will take off after those too.
I start early with name response with my dogs and building a positive association with coming to their name. This is a great tool as they get older for those situation when the leash is dropped, the door is open, the collar breaks, etc. By frequently reinforcing name response, there is a high likelihood that when I call their name my dog will respond. Of course, the higher the value the reward the more likely they will respond so when I am out I try to have very high value treats because I am going to be competing with some very rewarding distractions.
I do not allow my dogs off leash in areas that are unfenced and there is car traffic. I do take my younger girls on county walks away from car traffic offleash with a group of other dogs. They frequently "check in" with me for the treats and I do not hesitate to leash them up if I feel they are not paying attention to me or I do not trust them to respond because of the distraction. I am lucky to have areas that I can do this with my dogs but there are not many places where I feel comfortable doing so. Most of their walks are on leash and they really have no problem with that. They enjoy just getting out and reading the "pee mail" around the neighborhood.