You have mentioned that these traffic police constables expect bribes under the pretext of traffic violations. So, the best course open would be to complain to the Anti-Corruption Bureau or the Vigilance Bureau (by whatever name it is called in your state) and try to get them caught red handed while demanding and accepting bribe.
In fact, nowadays, most mobile phones have good cameras, which can record high quality videos. At least the audio recording would be available in most phones. So, you may try to record the video of the whole transaction when such traffic constable demands bribe from you. If possible, two motor cycles may be taken together to the spot, so that if bribe is demanded from one, the other can record the video. This may also be helpful in making out a corruption case against the concerned traffic personnel.
If you feel that this is not possible, then you can at least make a formal complaint to their senior officers with full details.
Dr. Ashok Dhamija is a New Delhi based Supreme Court Advocate and author of law books. Read more about him by clicking here. List of his Forum Replies. List of his other articles. List of his Quora Answers. List of his YouTube Videos.