Where I live, bicycles are widely accepted in traffic; motorists are on balance considerate and careful around us. But on an almost daily basis, I run into motorists who are too "polite" at intersections. They stop and try to wave me through when I have no right to be in the intersection and, in some cases, when it would actually be dangerous for me to enter.
Two examples come up most frequently:
At a four-way side street intersection, where I am at a stop sign and the motorist has no sign or signal of any kind. Usually the only vehicles visible are myself and the car. I usually try to wave them through instead, and give them a friendly "thank you, anyways" wave and a smile.
Crossing a busy three-lane one-way road, where I have a stop sign and am not moving, feet on the ground. Motorists in the lane closest to me like to stop -- with traffic now stopping behind them and streaming along beside -- and try to wave me past. Here I often pretend to not be paying attention, but usually have to resort to a vigorous "keep on going" wave, with the same "thanks" as they eventually give up.
I run into other configurations as well,* but the core issue remains the same: it's far easier, and often much safer, for them to just continue and allow me to move through the intersection after them.† When I'm stopped and the car is moving, it will be out of my way a lot faster than I can get moving and past. I really do appreciate their consideration, but in the broader picture, I'd prefer they just continue in their right of way as if I were another motorist.
Ignoring the stopped car has only mixed results. Are there any other tactics I can employ to indicate that I'm perfectly happy waiting, and keep these well-intentioned people from stopping in the first place, moving on their way and out of mine?
*One that causes genuine confusion is dual-purpose marked crossings, where the same sign indicates the presence of bikes and pedestrians. The latter should be yielded to here.
†In some cases I think they're even committing traffic violations.