Access tags on this road aren't accurate. Visitors aren't allowed to drive further than the gate, and have to use the Slieve League Lower Car Park. (Tags of the car park appear to be correct.) The part of the road between the lower and upper car parks (indicated as service road on here) appears to only be used by the buses (P+R) and taxis (maybe cars with a licence?), and obviously pedestrians.

Someone might want to review this in more detail. I merely visited the site; I'm not local to or familiar with the area, am not even an Irish or UK citizen.