You have asked a very interseting question.
I must say Kolkata Traffic Police is doing a good job. But there are certain areas which needs to be improved.
They need to be more strict with bus drivers, auto drivers, taxi drivers.
These people mostly violate traffic rules and harm the general public.
If these areas are looked upon then i can say Kolkata Traffic Police is the best!
It is not like I don't love my own city and I also must admit that the job of the traffic police in Kolkata is more difficult than any other metro city in India; nevertheless if you want to say that the Kolkata traffic police is the best among the country, I object. I personally feel that the Delhi police is much much better and are doing a very smart jobs almost unparalleled in the entire country. However this is just my personal view which might very well differ from those of other peoples.
I think traffic system in Kolkata is not so worse . How can anybody handle such huge numbers of cars . This is not their fault . It should have more lanes in kolkata . Otherwise the problem can't be solved.
" Failure is only a temporary change in direction to set you straight for your next success.
Only those who dare to fail greatly can ever achieve greatly. "
Number of cars may be much more in other cities, but the percentage of road kept for this city is much less than other cities. This is the expertise of Kolkata Police that they try to run the system with many limitations.