The M60 'smart' motorway has had no effect whatsoever, there is a junction every 1.5 miles on average so the speed management aspect of the system cannot work, the signs flash up to tell you to do 40 or 50 when you're hitting the back of stationary traffic
Cost hundreds of millions and took 4 years to implement and the reality is that it's only real benefit is to catch more motorists and to shovel public funds into government contracts