Delta DOES use jetways for RJs at at least one station: Daytona Beach. The jetway is angled downward, and a small metal ramp connects the doorway of the CRJ to the jetway. The ramp has handrails on the sides. To be honest, given the ineptitude of the Daytona Beach jetway "drivers" (imagine an 80 year old, easily excited grandmother driving a large, strange car for the first time, and you'll understand what I mean), I'd rather use the stairs.