As far as marking roads, planting signs won't be much, if any, quicker than painting stencils. The most time-consuming part is finding a place to pull your car over, then walking while you place three or more markers beginning 250 or so feet before each turn, then getting back in the car. Signs would be easier to do than paint with one person - because you don't need to put on and take off rubber gloves to get back into the car - but I much prefer sending road-marking teams out in pairs anyway, for safety reasons.