School buses are widely acknowledged as the safest way for children to get to and from school, but the nation’s top highway safety agency now says they’d be safer still if they all had seat belts and children used them, a dramatic about-face for the agency.

The National Highway Traffic Safety Administration stopped short of requiring public schools to start buying seat belts for all buses, but the agency’s new stance is nonetheless jarring. During its 45-year history, NHTSA has repeatedly looked into the issue and concluded that school buses were already very safe and that the safety gains from adding seat belts weren’t worth the expense.

Louisiana is one of six states with laws on the books requiring all school buses to have seat belts. The Legislature, however, never appropriated money to implement the law, approved in 1999. So buses in the state continue to roll without the safety devices.

Last month’s federal announcement has prompted discussion locally, but little change. School leaders say if required to, they will start purchasing buses with seat belts but several are reluctant to spend extra money — NHTSA estimates run from $7,300 to $10,300 more for a new bus — and express doubts about whether it’s a good idea.

“For drivers who own their buses or for some of the urban school districts that have larger fleets, that would be a monumental expense,” said Michael Faulk, superintendent of Central public schools.

The NHTSA’s announcement was preceded by a horrific school bus crash in Houston that focused public attention yet again on the issue of seat belts on school buses.

At 7 a.m. Sept. 15, a Houston school bus hurtled off an interstate overpass onto a surface street, killing two teenagers and seriously injuring two more students as well as the driver. The bus, as it turned out, had seat belts, but children in Texas aren’t required to wear them and these children weren’t.

Eight weeks later, speaking at a Nov. 8 conference of transportation leaders, NHTSA Administrator Mark Rosekind announced a change of direction.

“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. “That is true whether in a passenger car or in a big yellow bus.”

Days later, the Houston Independent School District followed NHTSA’s new guidance and decided from now on it will buy only buses with lap-and-shoulder belts, eventually replacing its fleet of 1,100 buses.

In Louisiana, East Baton Rouge Parish School Board Superintendent Warren Drake, who oversees the second-largest district in the state, has been one of the most enthusiastic about the idea. After Houston made its move, Drake said, he thought seat belts on school buses made sense and he’s asked his staff to see what it would cost to add them to the system’s 500-bus fleet.

In a Dec. 19 interview with The Advocate, Drake, however, was much more cautious.

“It’s not something we’re going to do this year, but it’s something we’re going to monitor and look and see,” he said.

Drake also said seat belts may at times prove counterproductive. He recalled a recent case in Baton Rouge where elementary children had to exit a bus when the engine started to emit smoke and soon caught fire. He wonders if they would have exited so quickly if they were fastened into seat belts.

John Watson, superintendent of Livingston Parish schools, said Livingston will comply with any changes in federal law, but worries it would be harder to replace his aging fleet if belts are required. At roughly $80,000 a pop, a new bus is expensive already, he said, noting that budget cuts in 2010 and 2011 led Livingston to buy no school buses at all.

“Anything that adds to the cost would be a problem,” Watson said.

Hollis Milton, superintendent of the West Feliciana Parish school system and president of the Louisiana Association of School Superintendents, said he plans to look into the feasibility of seat belts on buses for West Feliciana’s 30 buses, but said it will take time.

“This could be something where we work towards it over a couple of years, set some benchmarks,” Milton said.

School buses already have an enviable safety record. On average nationwide, just four children die aboard school buses per year. Compare that with the roughly 450 school-age children nationwide who die each year while riding in cars and trucks during school hours.

Smaller buses and ones that transport children to Head Start and Early Head Start programs are already required to have lap-and-shoulder seat belts. Big buses instead rely on high-backed seats and impact-absorbing cushioning to keep children safe in “compartments” during a crash.

While generally successful in preventing injuries during front- and rear-end collisions, compartmentalization falls short when a bus is struck from the side or rolls over. In those cases, unrestrained children run the risk of being tossed into aisles or onto the ceiling rather than against padding.

In September, NBC’s “Today” show broadcast video, supplied by NHTSA, showing what happens during such crashes. The agency’s simulation of a rollover, similar to the accident in Houston, was the most dramatic. Child-size crash test dummies not harnessed in seat belts flew out of their seats and bounced against the ceiling, while fastened-in dummies stayed put, emerging unscathed.

As recently as July, though, the NHTSA was much more cautious on the issue. In a presentation that month, NHTSA division head Shashi Kuppa suggested the increased cost of adding seat belts to school buses might have unintended consequences. For instance, if the added expense prompts school districts to buy fewer buses, some parents could opt to go the riskier route of driving their kids to school, possibly leading to an estimated 10 to 19 additional “transportation fatalities” a year nationwide.

Deadly school bus accidents often prompt calls for action.

In 2006, the governor of Alabama commissioned a study after a deadly accident in Huntsville. Similar to the one in Houston, four teenage girls died in 2006 after their bus plunged 30 feet off an interstate overpass; only three of 40 children on the bus were unhurt.

Released by the University of Alabama in 2010, the study found seat belts would make buses marginally safer — 0.1 lives saved, 8 injuries prevented each year — but the financial value of that increased safety didn’t outweigh the hefty expense. Extra spending, the researchers argued, would be better spent safeguarding children immediately before and after they board and exit the bus, an area sometimes referred to as the “danger zone.”

Part of the reason costs outweighed benefits is that many children don’t wear their seat belts.

For two years, researchers recorded seat belt usage on 12 school buses. About 61 percent of the time, children were observed using belts correctly. Eight percent of the time, they used them incorrectly. The rest of the time, they didn’t use them at all.

Kathy Keas, however, said she is sure almost all children would wear seat belts if they faced automatic suspension from riding the bus if they didn’t, similar to what happens now if kids get into a fight on the bus. Keas, president of the East Baton Rouge Parish bus drivers association and a driver herself with 30 years of experience, said identifying kids who disconnect their seat belts will be easy to prove given the prevalence of cameras on buses now.

“Once they stand up, that’s a dead giveaway. The camera picks it up immediately,” she said.

Keas said she also supports seat belts on buses for another reason: Improving student discipline. She said bus drivers risk accidents now because they are constantly having to look out for students wandering the aisles, getting into fights with other students and, in a couple of recent cases, even hitting the driver.

“In the last 10 to 15 years, it’s gotten worse. Half of my bus driving involves dealing with discipline,” Keas said. “Kids have totally changed. When they get on the bus now, they think it’s kind of a party.”

West Feliciana’s Milton said he thinks students will quickly get used to having to wear seat belts just as they adjusted to wearing them in cars when that became the law years ago.

“My kids, it’s so institutionalized,” he said. “If I don’t put a seat belt on, they will put a guilt trip on me.”