Given what I've seen here vs. in European countries with good driving test standards, I'm surprised it's not much higher. Maybe the distances in the US are larger? Or perhaps our roads are wider and so have more wiggle room, which compensates for the stunningly bad driver behavior I see every time I drive.
Which seems like a potentially reasonable policy tradeoff: make it easier for more people to get their licenses, then make it harder for them to kill each other. (NB I would prefer more stringent licensing standards).