Do mechanics need dot cards to road test trucks?

If they're operating them on public roadways, they need both a DOT medical card and the class of licence appropriate for that vehicle. In all actuality, the FMCSR states that anyone in actual physical control of a commercial motor vehicle must possess a CDL, but this is typically overlooked in instances such as mechanics on private property. However, the moment that vehicle enters a public roadway, it won't be overlooked anymore. Doesn't matter if you're 100 miles from the company's property, or only one foot from it.