I expect a constant review of the sensor performance and adjustment. The truck in question is part of a decade-old testing phase, according to the article. This will provide a lot of information, which can help navigate the issue of sensor interference.

Sensor malfunction was a constant worry when I worked on small robotics projects. I hope that car companies, which have much bigger resources than I can afford on my projects, will spend sufficient effort on making sensor interference and various malfunctions not degrade the operation of an autonomous vehicle.

There are techniques for reducing the effects of active sensor interference, for example:

http://www.cs.cmu.edu/~motionplanning/papers/sbp_papers/inte...

As long as the usable sensor density is higher than how tightly we can pack these vehicles, then we're probably OK.