Roads

Short
Wires down the centre of major roads to prevent head on crashes.
Better traffic management!
More contra-flow lanes, what a great idea.
Congestion charging will spread.
Automated traffic law enforcement, bus lane cameras in the U.K issue fixed penalties for driving in the bus lane using number plate recognition

Long
Cars that drive themselves at least on motorways, highways, speedways etc..as long as the insurance issues can be overcome.
Two way GPS so we can be aware of other traffic, i.e overtaking, traffic jams.
Automated traffic flow management, that releases traffic onto motorways when there is a gap large enough to avoid disruption to the overall traffic flow.
GPS monitored road pricing, more you drive the more tax you pay.