The days of school bus passengers riding unencumbered by seat belts may soon be over. This week, the federal National Transportation Safety Board made a recommendation to state agencies that new, larger buses should come equipped with lap and shoulder belts, as well as automatic emergency braking and anti-collision systems.

Traditionally, most large school buses have allowed students to ride without being secured in their seats. That’s because the buses are designed to surround passengers with shock-absorbing, high-backed seats spaced closely together, an approach referred to as "compartmentalization." In an accident, kids would be insulated in an egg-carton type of environment and prevented from hitting a dashboard or window. For smaller buses—usually defined as weighing 10,000 pounds or less—belts are standard.

The Safety Board’s conclusion comes at a time when recent bus crashes—including one with two fatalities that took place in New Jersey just last week—have reopened discussion as to whether larger buses need belts. The National Highway Traffic Safety Administration maintains that the compartmentalization of larger buses provides adequate safety, while the American Academy of Pediatrics argues that belts should be mandatory on all buses in the event of high-speed collisions or rollovers, where the high-back seats would offer less protection.

For now, the National Transportation Safety Board’s suggestion is just that—a suggestion. No states are required to follow the advice, and there’s considerable expense involved in retrofitting older buses with belts. Currently, eight states require seat belts on large buses.

[h/t ABC News]