 Highways England, the South Wales Trunk Road Agent (there are no motorways in North Wales), Transport NI (Northern Ireland) and Transport Scotland are responsible for the construction and maintenance of smart motorways in their respective countries.Variable speed limits with the hard shoulder operating as it would on a conventional motorway.They have most often been installed where a motorway has previously been widened but with a discontinuous hard shoulder to incorporate existing bridges, therefore using the hard shoulder as a running lane is ruled out.