The Welsh Ministers make these Regulations which impose a maximum speed limit of 40 miles per hour (instead of the general 70 miles per hour speed limit imposed on motorways by the Motorways Traffic (Speed Limit) Regulations 1974 (S.I. 1974/502)) on the lengths of the M4 motorway slip roads specified in the Schedule to these Regulations.
Link: The M4 Motorway (Eastbound and Westbound Exit Slip Roads at Junction 28 (Tredegar Park Interchange), Newport) (40 MPH Speed Limit) Regulations 2018
Source: Legislation .gov.uk
