Sure. Line scan indoor units are extremely affordable, and some cost less that $20, sold as spare parts for robot vacuum cleaners. Outdoor units (with higher ambient light tolerance and longer range) are an order of magnitude more expensive, but also available.
If one lidar hits another, it will result in at most one bad reading (perhaps a bad column?). This can likely be filtered, or a bad scan (360deg) can be altogether rejected and the data predicted using models based on past sensor readings.
I guess phase and timing sensitivity help a lot, because it's unlikely that another emitter will perfectly match your emission/detection duty cycle. It's also hard to get hundreds of cars at one intersection, because cars are very big.
The key terms in your literature/patent search should probably be "Crosstalk" and "multi-LIDaR".
Here is some detailed information about low cost units: https://github.com/kaiaai/awesome-2d-lidars/blob/main/README...
E.g Livox mid 360 https://store.dji.com/en/product/livox-mid-360
https://github.com/PiLiDAR/PiLiDAR
There's no way a sensor can tell if a signal was from its own origin?
Guessing any signal should be treated as untrusted until verified somehow
but I suspect coders won't be doing that unless it's easy
The key terms in your literature/patent search should probably be "Crosstalk" and "multi-LIDaR".