[kurthr]

In general this shouldn't be a problem, unless the receiver saturates due to a relatively wide time aperture. So long as the receiver remains linear and temporal/spatial/code filtering is operating properly, it shouldn't be a problem to have 1000 vehicles in range. Because of the truly absurd bandwidth of an optical system (100THz relative to GHz radio) it's possible to keep other systems out of band.

One advantage is that the average brightness will drop with a square-law from the other sources. This means that sources more than several hundred meters should have rapidly dropping effects on SNR. That doesn't mean that you couldn't do a particularly bad job of designing the receiver (intolerance to interferers) or a particular good job of designing a jammer (knowledgeable intentional interferer).