If that's implemented by way of some sort of public agency which obtains, analyzes, and releases sanitized versions of the data collected by self-driving cars f

If that's implemented by way of some sort of public agency which obtains, analyzes, and releases sanitized versions of the data collected by self-driving cars for the benefit of the public... then sure, that sounds like something we ought to do. But I would probably not phrase that as asking for a "central database" as though it's being fed by the cars themselves. That sort of centralization is... architecturally suspect, for a lot of reasons.