Nice video! The guy making this video gave a presentation at the annual gathering of the Dutch organization for reptile, amphibian and fish conservation last weekend. The road is fenced off at both sides of the passage, so the animals are "forced" to use the passage crossing the road, which is about 5-10 m long.
The passage was pretty well used; all reptile species occurring in that area used it. Also some smaller mammal species. Sometimes together, see at about 2:41 min...