M1 smart motorway upgrade cost £125mpublished at 08:28 British Summer Time 16 May 2019
Kevin Stanley
Reporter, BBC Radio Nottingham
Highways England has invested more than £125m upgrading a section of the M1 to a smart motorway.
It allows variable speed limits to be used on the section between Junctions 23a and Junction 25, which helps to adjust the flow of traffic to ease congestion.
Sensors by the side of the road work out when vehicles are slowing down, and signs above the carriageway change the mandatory speed limits accordingly.
Highways England monitors motorways and trunk roads from a series of regional control centres. Its operators can trigger various aspects of the smart motorway, including “Red X” instructions, which close one or more lanes at a time.