It has been reported that it was a constant struggle to get Urmson (the lead in Project Chauffeur) and Levandowski (who wanted to just launch) to work together

It has been reported that it was a constant struggle to get Urmson (the lead in Project Chauffeur) and Levandowski (who wanted to just launch) to work together because they had such a contradictory approach on safety. Urmson left in 2016, shortly before Chauffeur spawned into Waymo.