There are still some unknowns. Each car in the program (20 so far, 30 total) has a backup driver in case the system fails, and it's unclear how many of these trips required human intervention. It's also important to put Lyft's boasting in context. The company's overall service was racking up a million rides per day in 2017 -- 5,000 over the entire length of the self-driving program is a drop in the bucket. This is more about showing that the service has been hiccup-free than proving it was a resounding success.

Even so, it's good news for Lyft's widening ambitions. It already ran a self-driving test in Boston, but that was short-lived and confined to a small area. This shows that Lyft can sustain service over a significant period and a larger area (in this case, the Las Vegas Strip). The next challenge may be to scale to the point where Lyft can both cover very large areas and improve the reliability to the point where a backup driver isn't necessary. That might not happen for a long time given how cautious companies have been in the wake of Uber's fatal crash.