They would be allowed to send groups of self-driving cars on cross- state road trips, and even set up on-demand fleets of self-driving cars, like the one General Motors and Lyft are building.
2019年6月四级真题（第一套）阅读 Section A
柯林斯高阶英汉双解学习词典释义
N-COUNT
船队;舰队
A fleet is a group of ships organized to do something together, for example to fight battles or to catch fish.
A fleet of vehicles is a group of them, especially when they all belong to a particular organization or business, or when they are all going somewhere together.