Level Crossing (Coldagh) Order (Northern Ireland) 1998 No. 144

SCHEDULE 1 Particulars of the Barriers, Lights, Traffic Signs and other Devices

4.  When the barriers are fully lowered their uppermost surfaces shall be not less than 900mm above the road surface at the centre of the carriageway and the underclearance between the barriers and the road surface shall not exceed 1 metre.