Knoxville and Chattanooga lawmakers are teaming up in an effort to get seat belts on school buses after both cities lost children in school bus crashes in recent years. The bill is still in the preliminary stages.

Most recently, six children died in Chattanooga in 2016 when a speeding bus driver hit a tree. Two little girls and teacher's aide died in a December 2014 Knoxville crash when the driver was texting and driving.

Since then, parents and school districts have started looking deeper into the benefits and costs associated with putting seat belts on school buses.

Kingsport City Schools is one of the few districts in the state who has the safety restraints on all of its buses. The district added seat belts in the mid-1990s when it switched from contracting their transportation services to operating their own buses.

"We've made it part of the whole bus riding experience. We start with the little ones. Everyone is trained," said Tommy Starnes, the director of transportation for Kingsport City Schools. "Every year all of the elementary kids get a refresher course on the seat belts."

"We've had a lot of interests from other school systems who are coming and looking at our program," he said.

Starnes credits the seat belts for the district's safety record.

"Since I've been here in my tenure, we've never transported a student from an accident," he said. "That's a tremendous safety record we think. We have video on all the buses. Any time there's an accident you can see the results of wearing the seat belt. You can see that they work."

The National Transportation Safety Board agrees that in roll over crashes, three-point seatbelts are the best protection for students from injury. But the NTSB stops short of requiring seat belts for two reasons: school buses are still the safest way to get kids to and from school with or without belts, and they are expensive. The NTSB worries requiring them would mean less school buses are purchased and less students ride the bus.

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WBIR 10News wanted to see how Kingsport City Schools addresses the concerns that opponents argue are reasons to not have seat belts on buses.

1. Seat belts cost too much

It costs about $13,000 to retrofit an existing school bus with seat belts.

And statewide, officials estimate the cost would be as much as $33 million per year for the next seven or so years, according to a fiscal report.

Starnes said it's cheaper to buy a bus that's built with seat belts. That's how they've always done it. It adds about $3,000 per bus to buy one with seat belts already installed.

Kingsport also only transports an average of 2,200 riders a day, compared to Knox County Schools who transports 21,000 students each day.

2. Students can't escape in case of fire or emergency

Starnes said students are trained on how to unbuckle and evacuate in case of emergency every year.

His bus drivers are also required to have seat belt cutters within arm's reach at all times.

Starnes argued the safety benefits outweigh the risk, in his opinion.

3. Fit less students on a bus

Without seat belts, in many districts, schools fit three students to a seat. With seat belts, that's nearly impossible for older children and teenagers.

Starnes orders buses with two and three seat belt options so students could fit three younger children or two older children in a bus seat.

Bus drivers in Kingsport prefer their students in seat belts because it provides fewer opportunities for distractions.

"It definitely keeps everyone in their seat because they don't want you to know they're not wearing their seatbelt," said bus driver, Billy Nelson.

Nelson can't imagine driving a bus without seat belts. He's been driving a bus for Kingsport for 17 years.

"I probably wouldn't drive a bus if it didn't have a seat belt. I wouldn't drive my kids in my own car without a seatbelt. It would really be hard on my conscious to do that," he said.

In Kingsport, the district requires students to buckle up or be written up.

"Usually if the parents are teaching their kids to wear seat belts in the car then the child knows pretty much when they come to the school bus how to fasten the seat belt,"

As a back up, the bus drivers do a walkthrough check with elementary students before leaving.

Nelson says it's a duty that he's happy to add to his checklist. If there ever is a crash on his bus, he believes the seat belts could save lives.