 For example, a section of the N1 from the northern end of the M1 motorway (north of Dundalk to the border with Northern Ireland) has a 120 km/h (75 mph) speed limit.Signage on Irish HQDCs is similar to signage used on Irish motorways, and junction numbers may be present (as on motorways, indicated by a white number on a black panel in the corner of signs).However signage on HQDCs uses a green background instead of the blue background used on Irish motorway signage.