I made a joke about this once and my friends were like " that wouldn't work, you'd get stuck in a corner" after reading your comic for the first time, I fell in love with it. That seems like something jenny would do, but what about spitters?
Actually, that does make absolutely perfect sense. Make it out of a transparent aluminum carbon composite, give it a Teflon and Kevlar coating and all the person inside would need is a way to effectively move air rapidly inside the ball so they don't overheat, food and access to water. Maybe even give it little ridges in the event they fall into water so they can at least paddle themselves back to shore. Yea, the safety solution for a post zombie world is a human sized hamster ball.