I really doubt whether the traffic police personnel know the rules themselves. vehicle cross the red light s,, vehicles jump the red lights when the traffic police is there. The traffic police officials stand there as silent spectators.
Since they earn lot of money as bribe from trucks and other vehicles, their annual increment should be stopped. And also the traffic police men, those do not work, they should be given VRS and new educated men should betaken thru stringent selection process.