I would think bang for buck it would be a lot cheaper to put...

I would think bang for buck it would be a lot cheaper to put some type of retarder on the engine  or transmission to supplement a garbage truck  in slowing  down for each stop then override the last part of the stop with the standard brakes than go for the high CAPEX needed to install SIBS .
Modern retarders are quiet to :
Looks like these guys are ahead of me ,and given the name Allison who would you buy from Allison or some unrecognisable  outfit out of Perth ?

http://www.recyclingproductnews.com...-now-available-for-freightliner-m2-112-trucks

I hold as see potential in the utility and  18 wheeler trailer market not garbage truck market .