The Rhode Island Department of Environmental Management has proposed expanding its emissions inspection program to include big trucks and buses. The state is also considering stricter standards.

Since the program was started in January more than 55,000 cars have been tested and about 3,400, or 6%, failed. State officials say current standards are designed to catch the worst violators. Stricter standards could increase the failure rate to 20%.
A legislative committee on energy and the environment plans hearings to determine if changes are warranted.