In huge cities like in Brazil...where they are into practicality over anal WHS...taxi choppers are routinely used to get across town...direct building to building top, saving great swags of time,by not battling the traffic on a circuitous route to get there.
Quieter drones will eventually be the replacement vehicle.
They can have a little red flag out the front too...but to indicate slip or skid as they go.
Probably have a ex Mars Robot, back on Earth after a re-fit as a "driver"