score:1
The answer to this is: Fairly.
I didn't use a colectivo in the end myself - for our group and distance, a Taxi only cost 30 MXN more. The walk from the highway is real, but probably only 500m - 800m or so. There is a sidewalk on the highway overpass (if you need to get to/from that side of the road). Once over the highway there is a footpath seperated from the road to take you to the entrance.