Restricting trucks over a certain weight between 6am and 8pm - although I'm sure this rule is already in place in parts of Qatar but is it enforced?

Like so many traffic laws here, ignoring them until you get the bill from the MOI seems to be the norm. If there were enough police manpower to stop offenders, issue fines on the spot then I believe that many poor drivers (speeders, drifters, dangerous lane changes, driving on the hard shoulder, I could go on and on) would stop offending.

In Dubai, once the police were posted on the Dubai Sharjah Road to immediately stop and ticket hard shoulder drivers - it stopped happening.

Here in the Gulf, people speed past the police vehicles with impunity because they know they won't be stopped. In North America and Europe and Australia - when you see a police car, you slow down.