Bribes are not the thing Thai policeman hunting from despite of foreigners’ point of view. No one would stop you and make any obstacles to receive a bribe.
But in case you had really disobeyed the traffic rules and policemen preparing minutes and fine bill you have two options: take the fine bill, take taxi and drive to the nearest police station by yourself or ask policemen to do everything by himself for an additional small “gift”. In this case policemen would decide to make a favor for you or not.