Why Seat Belts on School Buses Aren't Mandatory in Every State

— -- In the wake of a horrific school bus crash in Chattanooga on Monday that left five young children dead and a bus driver behind bars, some critics are calling for stricter bus regulations and the increased use of seat belts.

Here’s a look at some of the safety regulations regarding school buses.

School Buses Are Safe, Right?

Despite parental and community concerns, riding in a school bus is still safer for your child than riding in a minivan or walking to school, according to the American School Bus Council and the National Highway Traffic Safety Administration.

"Students are about 70 times more likely to get to school safely if they take the school bus instead of traveling by car," the ASBC explained on its website.

A School Bus, Defined

A school bus is any passenger vehicle that is designed to carry more than 10 passengers (in addition to the driver) and is used for the primary purpose of transporting pre-primary, primary or secondary school students from home to school or school to home, according to the Federal Motor Carrier Safety Administration. But despite being defined by a federal agency, local government entities actually oversee public school bus regulations.

For example, Hamilton County, Tennessee, is responsible for all rules and regulations regarding any operation of public school buses within its jurisdiction, including the bus that crashed in Chattanooga on Monday.

The Driver

According to Hamilton County's Department of Education, all school bus drivers are required to maintain a valid "non-restricted commercial driver's license with the required endorsements for the vehicle their job assignment requires." Drivers are also responsible for attending drug and alcohol training, and in the case of an accident in which children are injured, drivers are mandated to submit to a drug and alcohol screening. Drivers are not allowed to use their cellular phones while operating the school bus, according to the county's rules.

In the case of an accident, the county instructs its bus drivers to exercise caution when discussing the event.

"DO NOT admit any guilt to anyone. Only discuss the accident with the police officer, your supervisor, or the School System's Administrative staff," Hamilton County's website states.

The Story Behind Seat Belts

While only six states require seat belts on school buses -- California, Florida, Louisiana, New Jersey, New York and Texas -- nonprofit organizations have for years encouraged the use of seat belts on school buses.

However, it was only last year that NHTSA Administrator Mark Rosekind came out in favor of lap and shoulder belts on buses.

"NHTSA has not always spoken with a clear voice on the issue of seat belts on school buses. So let me clear up any ambiguity now: The position of the National Highway Traffic Safety Administration is that seat belts save lives," Rosekind said in November 2015.

But in an interview with ABC News' David Kerley later that month, Rosekind explained that while there is no federal mandate yet for safety belts on school buses, bus manufacturers could start installing seat belts on school buses.

"They don't need a rule from Washington to start putting 3-point belts on buses today," Rosekind said, adding that his agency was looking for other ways to help get those belts on buses.

"We're gonna start everything -- from research to looking for funds -- to figure out how to make this happen," Rosekind said. "The sooner we get this done, the more lives we can protect. The more injuries we can prevent."