It looks like it may be an automatic system with manual override...
"M1 Junction 10-13 Improvements"
"Following careful assessment, the comprehensive safety study shows that the managed motorway can be operated safely without lighting. As part of any managed motorway system, CCTV cameras are installed for traffic monitoring: those on this section of the M1 will be 'low light' cameras to enhance the capability of staff in the Regional Control Centre to monitor the M1 24 hours a day."
There is an email address on the above webpage if you want to contact them.
There is an FAQ section in this direct.gov.uk document on the M25 traffic control system which has a go at giving an answer to one of your questions I think.
Two wikipedia pages
"Active Traffic Management"
Maybe traffic management is too narrowly defined.
Perhaps non urgent car and lorry traffic can be discouraged (using tax) from travelling on managed sections in peak hour travel times. i.e. by asking car owners and lorry operators that wish to travel through managed traffic zones at peak times (morning and evening more than 4 times a week) to pay an extra fee that is added onto their yearly road tax.
Widening the roads doesn't seem to work for long as it just encourages more traffic at peak hours. According to an AA survey I can't find now quite a lot of people don't feel comfortable driving on a motorway without a hard sholder.