The 6 meter hydraulic CADO guide rail was the first automatic highway median emergency access gate,  designed and build together with the Dutch Road Authorities (Rijkswaterstaat). In spite of the slow demand nowadays you still find them well functioning on several locations in the Netherlands.

Especially in assembling a couple of hydraulic CADO calamity passages next to each other, there is a cost advantage in operating them through one and the same hydraulic unit.