The interesting thing is that traffic congestion for cars in the downtown core didn't change at all! The study found that average car travel times on adjacent streets vary by less than a minute compared to before the pilot.
Shorter range lidars (<10m) tend to work in the frequency domain because you can get pretty good ranging accuracy.
Longer range lidars work in the time domain. The SPAD detectors used by Ouster create a pulse when a single photon is detected and so you're measuring the time of flight of the photon being emitted by the vscel and then being detected by the SPAD array.
Velodyne lidars have a phase lock feature so that each lidar is out of phase with each other to prevent interference patterns. This is a bigger issue with sensors that are permanently mounted together but it'll also occur when there are many autonomous vehicles driving together.
Just another of the many edgecases to figure out before autonomous vehicles become mainstream.
The interference will most likely show up as noise. Its SPAD detectors have high noise compared to APD so the increased noise due to interference with other lidars would be minimal.
The laser isn't tested to IEC60825. Instead the manufacturer (Oester in this case) would submitted information about the laser scanning system design to the FDA to get approved as a Class 1 device.