Actually, coincidentally, I have been pondering whether we might have to resort to motor vehicle style traffic lights and maybe even roundabouts or give way junctions on airfields one day?
There are an awful lot of radio transmissions involved with taxying at large or busy airfields these days, so perhaps a system of traffic lights might be part of the answer?
We already have red stop bars of course, but would there be any reason not to have traffic lights at each junction with say green arrows which illuminate at the appropriate time to tell us that we were cleared onwards, and which way to turn? This might be easier and cheaper to implement than the long rows of green lights on the taxiways seen at Heathrow and Gatwick etc.
I would envisage that important clearances such as lining up, taking off, or crossing active runways should still require voice clearance and readbacks.