The detection of the cones isn't the problem. The software properly identified that there were cones near the roadway, that's why it stopped. The really hard problem is programming decision-making logic that will properly ignore cones that aren't in the roadway, 100 times out of 100.
I used to do QA for the Waymo cars, and boy do they get worked into a tizzy if there's any kind of construction going on. It was the most common situation for remote assistance (read: people sitting in a room sending pathfinding suggestions) to get involved.
Judging from some of these comments, the problem is still very difficult.
I can see the 007 getaway now. With a press of the button, a bunch of tiny transponders are thrown on the road. The bad guy's cars automatically brake because they can't find a way to get around the new obstacles.
And when all the cones' fancy electronics break or aren't charged? Is the cop just supposed to not stop? What about poorer jurisdictions that can't afford it?
And if the officer puts down a regular cone and the driver is texting and doesn't see it? Like, yes this would require changes to how we do things. Police officers will have to be careful to use the new style cones correctly. Is this any different than when they first started having use cones/flares? There is a price for every technology. I mean one of the alternatives is that we rely on the LIDAR being so good as to not hit the car and the officer standing next to it because it recognizes that situation. Which it will. Most of the time. Until it doesn't. Seems to be that having the transceiver and LIDAR backup is better than fancy expensive LIDAR.