The Transportation Department proposed establishing minimum testing and licensing standards, to be implemented by the states, for commercial truck and bus drivers. Under the department's Federal Highway Administration standards, about 5 1/2 million drivers would have to obtain such a license by April 1, 1992. The question of whether states would develop a plan for testing and licensing or whether the federal agency would provide for specific guidelines has not been resolved. The government plans to issue the final standards next summer. Currently, some drivers who are penalized for unsafe operations get a license from another state and keep on driving.