There's a few things that fall under the "smart motorway" umbrella. They also have systems to detect traffic flow and impose variable speed limits when approach

There's a few things that fall under the "smart motorway" umbrella. They also have systems to detect traffic flow and impose variable speed limits when approaching a queue, and usually regular speed cameras to enforce those limits. This stopped car detection thing is indeed about the ones that can open the hard shoulder for traffic, though.