For decades, automakers have mounted front seat tracks to the vehicle floor with a bolt at each corner. That's four bolts per seat, and you can usually see them just by looking down. Rear seats are also bolted to the vehicle's body structure.
But that simple, safe and secure way to install seats quickly and accurately on the production line is likely to get a lot more complex in the era of self-driving vehicles. Several suppliers are testing prototype interior modules in which the front and rear seats are mobile, flexible and configurable.
That scenario brings an array of engineering challenges that will test safety experts in new ways. Airbags, seat belts, how the vehicle's structure manages energy in a crash, and even electrical parts will change as seats become more versatile.
"Small changes to the interior can have a dramatic impact on safety," said Steve Peterson, vice president of engineering at German supplier ZF. "When you change the seating, current restraint systems are either going to be completely or somewhat ineffective."
French supplier Faurecia believes as many as 15 percent of the vehicles sold by 2030 will have Level 4 autonomy or higher, meaning they will drive without input from a human. If the vehicle drives itself, that frees up the motorist to do other things, and he or she might not be facing forward. But even though safety is expected to increase with self-driving cars, they will share the road with human-driven vehicles, meaning accidents will still happen.
"Today safety is the highest priority, and this is going to be the same in the future," said Dirk Brassat, Faurecia's vice president of engineering seating in North America.
Faurecia, in its joint venture with ZF, is working to perfect light but strong seat structure technology, while ZF is developing safety technologies dealing with seat belts, pretensioners and airbags.
"We cannot reduce any safety requirements, especially when you go into different seating positions," said Brassat.