http://www.legislation.gov.uk/uksi/2015/1701/signature/madeThe M1 Motorway (Junctions 28 to 35a) (Variable Speed Limits) Regulations 2015enKing's Printer of Acts of Parliament2015-09-25ROAD TRAFFICSPECIAL ROADSThese Regulations introduce variable speed limits to the M1 Motorway from junctions 28 to 35a and on associated slip roads and linking carriageways.Signed by authority of the Secretary of State for TransportRobert GoodwillParliamentary Under Secretary of StateDepartment for Transport18th September 2015