A federal crackdown on unsafe bus operators in 2012 coupled with the sluggish national economy has allowed conventional and discount operators to thrive, researchers said Sunday at the American Bus Association convention in Charlotte.

“It’s a happening sector right now,” said DePaul University professor Joseph Schwieterman. It was a glowing review for an industry that has had its share of controversy in recent years.

In 2012, the government cracked down on a number of low-fare bus companies that were shoddily run and did not follow safety regulations. Some of those companies with the worst safety records in the nation included Ming An Inc., Blue Sky Bus Tours Inc. and ABC Tour.

Those companies, which offered cheap fares to major cities, had grown rapidly in the past decade, but their safety records marred their reputation. In May, the Federal Motor Carrier Safety Administration shut down 26 of the worst violators.

During Sunday’s presentation, Schwieterman discussed several key findings from the university’s research:

• Intercity bus service, or service from one city to another, increased by 7.5 percent between 2011 and 2012 – the highest rate of growth in four years.

• Daily bus operations by discount city-to-city operators such as Megabus and BoltBus increased from 798 to 1,052 between 2011 and 2012. Such operators typically do not use traditional terminals.

• Although annual growth of intercity bus services declined from the 1960s to 2006, it started increasing in 2007. That growth has continued to the present, with the annual growth of services up by 7.5 percent in 2012.

• Comparatively, rail increased by 3 percent between 2011 and 2012. Car increased by 0.4 percent during that time, and air travel increased by 0.4 percent.

Bus lines Greyhound Express and Peter Pan Express have seen dramatic expansions in recent years. For instance, Greyhound Express launched a number of niche market campaigns, including one aimed at Latino travelers that is provided in the California corridor of Los Angeles, San Diego and San Ysidro.

Researchers also attributed the growth in the motor coach industry to a sluggish economy that has made buses – some of which offer $1 tickets at times – more desirable.

“It’s cheaper than flying and rail. That’s why you’re seeing an increase throughout the recession,” said researcher Paige Largent of DePaul.

A string of high-profile accidents leading up to the 2012 government crackdown had some questioning whether riders were trading safety for affordability.

In May 2011, a bus operated by Charlotte-based Sky Express crashed, leading to the concentrated effort. In that case, a fully loaded motor coach drifted off Interstate 95 in Virginia and overturned, killing four passengers.

Investigators with the National Transportation Safety Board concluded the driver fell asleep, and they also faulted the Federal Motor Carrier Safety Administration for not shutting the company down sooner. Sky Express had one of the worst safety records in the nation before the crash.

In response, a law took effect in October that requires higher training and record-keeping standards for drivers and improved federal registration to detect shut-down companies that have “reincarnated” and are operating as new carriers.

Known as MAP-21, the law also requires seat belts for passengers, stronger bus roofs to prevent crushing and design features to keep passengers from being thrown from the bus if there’s a crash.

Pantuso said that he is pleased that the FMCSA will more throughly enforce existing motor coaches and those entering the industry.

He added that the higher cost of starting a motor coach business should help keep shady bus operators out of business.

Researchers said that the closing of dozens of motor coach companies after the government investigation in 2012 gave remaining companies the opportunity to expand to those affected areas.

Largent said Sunday that she is optimistic about the future of motor coaches.

“I don’t anticipate a decrease because the cost is still going to be less expensive than flying and Amtrak,” she said. “If anything, I expect it to continue growing.”