https://www.cnbc.com/2018/03/23/ubers-self-driving-cars-were-struggling-before-arizona-crash.html

Uber's robotic vehicle project was not living up to expectations months before a self-driving car operated by the company struck and killed a woman in Tempe, Ariz.

The cars were having trouble driving through construction zones and next to tall vehicles, like big rigs. And Uber's human drivers had to intervene far more frequently than the drivers of competing autonomous car projects.