Ah, I meant for humans. As in, how much is depth-perception actually necessary for driving... Obviously, humans also use higher-level cues, which IMO are much more important.
Whoops, my bad for skimming the comments and overlooking the context of your question.
I found a page [1] that summarizes the level of visual acuity required to obtain a driver's license in each US state. It appears that all states will potentially issue a license to someone with vision in only one eye. Some states impose additional conditions, such as requiring a favorable report from an ophthalmologist, limiting the maximum speed, or restricting the driver to vehicles with outside rear-view mirrors (to compensate for the loss of peripheral vision on one side).
