Problems with Array Assignment?

[Samwise via Digitalmars-d-learn]

I'm really sure this is just a stupid mistake I made, but I can't 
for the life of me figure out what is going on. Basically I'm 
trying to assign a reference to an object to an array, and the 
objects exist (an explicit destructor is writing lines at the end 
of the program, when the objects are GC'd), but there are not 
references to them in the array. You can see the complete code, 
and the line that I think is giving me trouble here: 
https://github.com/MggMuggins/TrafficLights/blob/master/source/renderer.d#L146

Any help is greatly appreciated. Like I said, I'm sure it's just 
a silly mistake because I don't understand something, but I 
appreciate any time you waste on me all the same. Thanks,
~Sam