I might be a moron here, but I have no idea how to interpret this. Is each blue bar the proportion of streets that run in that direction? Do the ones that just have a single bar at N/E/S/W have perfectly aligned streets that only go in the cardinal directions?
Even if you perfectly solve crashes (doubtful, definitely not something that exists right now), the problems of microplastic pollution from tires and emissions from electricity generation are non-trivial.