Currently, our intersections are highly hackable because of the way our traffic lights work. We should replace those traffic lights with roundabouts.
Many modern traffic lights are connected to emergency-response systems. If those systems are hacked, it could lead to massive crashes at major intersections.
Meanwhile, roundabouts can't be hacked because they're low-tech and built into the roads.
Plus, roundabouts are energy-efficient because cars use less gas going around them (less stopping and accelerating), which can lower gas prices and help us be less dependent on foreign oil.
A multi-year construction program in major cities could diminish this vulnerability that hackers might otherwise take advantage of. It would also be a good use of our military budget.