AUSTIN, Texas Concerned about a multi-fatality motorcoach accident involving a rogue bus company this past summer, transportation authorities here have stepped up their hunt for other unsafe bus companies that might be operating in the state.

The state Department of Transportation is attempting to contact the owners of the more than 200 motorcoach companies that lost their state operating authority during the past 24 months to determine if any of them are still in business and operating illegally.

The companies lost their operating rights for a variety of reasons, including allowing their liability insurance to lapse, failing to re-register their buses, closing their businesses, and driver and vehicle safety violations, said Robert Anderson of the agencys motor carrier operations section.

Many of the revocations occurred, he said, because the operators failed to maintain their insurance, although some of them renewed their policies days or weeks later and continued to operate in good standing. It is not known how many had safety or driver issues that resulted in revocations.

The research was ordered by the transportation department following an Aug. 8 accident in which a motorcoach blew a tire near the town of Sherman, north of Dallas, and overturned, killing 18 passengers and injuring 30 others, a number of them critically.

Investigators said the coach belonged to Iguala Busmex, a Houston-based company formed three days earlier by an operator who had recently had his operating authority revoked for another company because of safety violations.

Within weeks of the accident, two other companies were shut down because of their affiliation with revoked companies.

The situation with rogue companies, especially the deadly bus accident, troubled transportation authorities and led to the order to check all companies that had been put out of service in an attempt to identify and locate any other unlicensed carriers that might be operating in the state.

"We wanted to be proactive," said Christy Bird of the transportation departments registration section.

To operate in Texas, motorcoach companies are required to carry between $1 million and $5 million in liability insurance, pay one-time fees of $200, and register their coaches annually for $10 each. As of late August, there were about 360 motorcoach companies with 4,700 coaches registered in the state.

Anderson said that while the review of the 200 companies is well under way, a running account of the number of owners who have been located and those that continued to operate without regulatory authority is not being kept.

"We dont have all of the answers yet," he said, adding that no deadline has been set to complete the study.

Anderson said companies caught operating without regulatory authority will be ordered to register with the state -- if they want to remain in business. They also could be assessed an administrative fine for failing to register and be penalized for possible safety violations if any of their coaches are found to be unsafe.

"We look at the reason and if there are no accidents or public harm issues and they act quickly to get back in, then all they might get is a formal letter of warning," he said. "For more extreme measures, our investigative and enforcement people can fine them or order them out of service."

He noted that while the records show that about 200 companies lost their operating authority in the past 24 months, many of them may have been off the books for only a few days.

Thats because the state database keeps tabs on the date each companys insurance is to expire and if an operator does not file the renewal information on time, the system automatically pulls its operating authority. However, if the paperwork is filed within a couple of days which is often the case then the carriers authority is restored, although the revocation remains part of the total statistics.

Meantime, the Texas Department of Public Safety also is looking for rogue operators as part of its regular motorcoach safety inspection program, according to Capt. David Palmer.

Although he was unable to say how many coaches have been found to be operating without state authority, he said those that are identified are ordered off the road and out of service immediately.

"Our emphasis in the inspection program is on safety," he said, adding, though, that a check for federal and state operating authority is always part of each inspection.

The police agency, which works closely with state and federal transportation regulators, does about 23,000 terminal, roadside and destination inspections of motorcoaches and buses in the state annually.

Palmer said police also are paying close attention to buses that come across the border into Texas from Mexico, some of which have been involved in serious accidents in the state.

"We try to place added emphasis on motorcoaches and buses coming across the border because of the accidents," he noted.

Palmer said the inspection of the Mexican motorcoaches is hampered by logistics and the design of the border stations.

Motorcoaches cross into the U.S. at the same border stations as automobiles, while commercial trucks and there are many more of them than buses cross at other locations.

The border stations where cars and buses are allowed to cross were not designed for bus inspections and there are almost no areas where an inspection can be conducted safely.

"Its kind of hit and miss because we cant always have someone at the bus crossings," said Palmer. "So, we can only do a limited number of inspections." Palmer said some Mexican buses that are missed at the border crossings do get inspected when they are stopped as part of routine roadside inspections.