This rule is like pedestrian life, but traffic lights work because of the 4t transition.
there is a semi common p2 oscillator (in D4+1) which is made of 4 Billard tables that need each other to be stabile.
There has been a small amount of discussion of this rule in the Rules 2 Transitions from Life thread. Here's the earliest mention I found: viewtopic.php?p=144762#p144762
The main interesting object is a 21c/83 block puffer made of two B-heptominos.