Even though buses represent the fastest-growing segment of interstate travel, regulation of the industry has lagged, potentially putting passenger safety at risk.
A Boston Globe analysis of federal data has found that one in four of the more than 3,700 commercial motorcoach and passenger van companies regulated by the federal government has never received the full safety evaluation.
Of those that have been inspected, problems uncovered range from unqualified and over-tired drivers to unsafe vehicles.
More than 200 companies with at least one safety alert for serious violations uncovered by local authorities have not undergone a complete federal safety review in at least two years.
Anne Ferro, head of the Federal Motor Carrier Safety Administration, says her agency has neither the money nor the manpower to adequately monitor the bus system.