On the outside, school buses don't look a lot different from how they looked half a century ago. But those who work in pupil transportation know that the yellow school bus has changed immensely, from enhanced federal motor vehicle safety standards to the addition of new technology.

One of the many significant developments over the decades has been in the seats. For example, if you've been in the business a long time, or if you rode the school bus as a kid, you may remember that the metal seat frame used to be exposed in the back — a far cry from the thick padding that's in place on today's seats.

To educate the public on how much school bus seats have changed and school bus safety has increased, a group of pupil transportation people in North Carolina put together an innovative exhibit.

"We decided to take a retired bus that was still in decent shape and convert it to be used as an educational bus," said Derek Graham, North Carolina's state director of pupil transportation. "And we decided to include a variety of seats to show people how much progress has been made over the years."

Graham's office collaborated with Durham Public Schools on the project. Marlon Watson, the district's transportation director, selected a bus, and mechanic Buster Smith worked on removing the seats and devising a way to run the bus' eight-light system and stop arm while the bus isn't running.

Keith Whitley, field transportation consultant for the state office, went out to junkyards and found a range of old school bus seats — from as far back as 1953. Also, Durham Public Schools had some 1980s and '90s seats in its garage.

The seats were installed in the educational bus, and Smith reconfigured the bus' wiring so it could be plugged into a drop cord without running off of the battery (to demonstrate the lights and stop arm). The Durham Public Schools team also did some detailing and painting to spruce up the bus.

In October, the bus went on display at the North Carolina State Fair. Children and parents could walk down the aisle to see the progression of school bus seats from 1953 to 2013. Also, a television on board played school bus safety videos.

Watson said that fair visitors found the display informative.

"I think it was very effective," he said. "It was a drastic change from the '50s and '60s to what we have in today's buses."

"A lot of people my age and older would say, 'Oh, I remember this seat. That's the one I rode on,'" Graham added. "It got a fair amount of attention."

The educational bus will return to future fairs and may also be taken to other sites during the year.

To see a variety of photos of the bus and the different seats, check out our photo gallery.

— Thomas McMahon, executive editor