The New York Police Department has proposed new rules regulating public gatherings and protests. For the first time, any group of 30 or more vehicles or bicycles would be required to obtain a police permit, even if the group was obeying all traffic laws. The police proposal also would allow the arrest of any group of 10 or more if any member of the group violated a traffic rule. The New York City Bar Association, New York Civil Liberties Union, United for Peace and Justice and other groups oppose the rule changes. The police department is holding a public hearing on the issue today.