When walking or driving a car around an airport, airplanes should always be given the right-of-way. Remember that you can more easily see the airplane than they can see you.
Even if an airplane’s engine is not running, you should pay attention. Any aircraft with people inside of it or any lights illuminated should be treated with extreme caution and an extra wide berth. Don’t count on the pilot noticing you.
I’ve had several cases recently of people coming very close to an airplane on foot and on a bicycle, just as we were about to start the airplane. In both cases, the airplane’s beacon was flashing and we had yelled “CLEAR” in preparation for starting. Even with those precautions they came much closer than I felt was safe.