[rcarr]

There's lots of second and third order effects I think. Traffic reduction and pollution reduction should result in a decrease in lives lost to accidents and respiratory diseases. Reduction in traffic could lead to uptake in cycling and outdoor activities and a healthier populace. Reduction in pollution could be better for ground based wildlife and the environment. I imagine there's significantly less cost both in materials and maintenance for a drone vs a van so that could end up being passed on to the consumer. Possibly personalised delivery times as the drone could theoretically delivery whenever.

A possibly more dystopian one: likely to have all manner of cameras and sensors on board that will probably be used at some point as evidence if a crime if committed whilst the drone is passing by the area.