A lower national speed limit by stealth, coupled by the inevitable average speed cameras*? There's miles of them on the M1 around Sheffield, and on the M62 around Bradford/Huddersfield. Allegedly they're replacing the crash barriers and/or redoing the hard shoulder - although it's miles and miles of empty roadworks and two lanes with only a small area of work.
*Does anyone know if they work, or if anyone has been caught by these, or is it yet another example of the Govt lying to us?