This sounds like an overly-expensive implementation of the simple strobe-based signals used in the U.S. at nearly every intersection I've been through.
If there is traffic crowding and narrow lanes or lane sharing then the ambulance needs the drivers in front of it to also realize they have right of way and the obligation to continue moving out of the way.
This is a common problem in older US/European cities where the streets have not kept up with capacity and are not as wide as would be required by current rules.