Not to be outdone by their more numerous light-duty siblings, medium-duty trucks covering Classes 4-6 have been the object of a flurry of development and experimentation the last few years. They're often on the job with upfit bodies of various kinds serving trades and utilities or handling last-mile and metro/urban-area deliveries and distribution, and they have the benefit of not requiring a commercial driver's license to operate. That adds to their appeal, since fleets can hire drivers from a much larger potential employee pool. Not only do these trucks have impressive capabilities, their typically shorter-range duty cycles have also made medium-duty trucks good candidates for electric power.