A rolling road is another term for a chassis dynamometer.
A rolling road is different in that the floor moves under the car, not just rollers under 1 or 2 axles. Like this http://www.qmtmag.com/images/Windshear_RR_05.jpg The chassis dynos are noisy, these are super noisy.
Disclosure: I sold Maha dynos from 96-2000 with SnapOn/Sun branding, about 40 of them.
I'm a fan of names that give insight into what the thing/product/service/company actually does.