Chairman of the Association Gemunu Wijeratne said a gazette notification was issued citing that the priority bus lane is allocated for buses.
When inquired by NewsRadio Wijeratne said the number of accidents could increase if motorcyclists attempt to manoeuvre between buses.
He said therefore all buses, three-wheelers and motorcycles will be required to travel along the left from tomorrow.
Gemunu Wijeratne said the decision by the Police is a violation of the law.
He also claimed that three-wheelers can travel at 40kmph while buses travel at between 60-70kmph.
He said the Association tabled several proposals to the government including amending office and school hours, and preventing heavy vehicles from entering Colombo and congested area during peak hours.
He said bus operators will withdraw from services in protest if the decision is not revoked.
The Police said three-wheelers and motorcycles will be directed to priority bus lanes assigned along several roads in Colombo from tomorrow.
The Director of Motor Traffic and Road Safety SSP Indika Hapugoda said since a majority of three-wheeler drivers and motorcyclists failed to adhere to the new regulation, heavy traffic was observed in certain areas.