WASHINGTON A new federal rule requiring higher seat backs, mandating lap and shoulder belts on small school buses and setting safety standards for seat belts on large school buses has been issued months before it was expected.

The rule is designed to make the nations 474,000 school buses safer, said U.S. Secretary of Transportation Mary E. Peters.

"Even though riding in school buses is the safest form of travel in America today, any accident is still a tragedy," said Peters. "Taken together, these steps are designed with a single purpose, making children safer."

Peters said the new rule requires all new school buses in America to be equipped with 24-inch-high seat backs, instead of the 20-inch-high seat backs required today. Higher seat backs will help prevent taller and heavier children from being thrown over the seat in a crash, decreasing the chance of injury to them and the children in front of them.

All new school buses weighing less than five tons will be required to have three-point seat belts. She said lap-and-shoulder belts better protect children in small buses, adding that smaller school buses are more vulnerable because they dont absorb shock as well as larger buses.

The secretary also said the federal government would be setting new standards for seat belts on large school buses. The standards will improve seat belt safety and help lower the cost of installing the belts. She cautioned, however, that seatbelts on larger buses can limit capacity and force more students to walk or ride in cars to school, which is statistically more dangerous.

"The last thing we want to do is force parents to choose other, less safe ways of getting their children to school," she said. That is why she said the federal government also would begin allowing school districts to use federal highway safety funds to pay for the cost of installing belts.

"No school district should have to choose between books and safety," said Deputy Transportation Secretary Thomas Barrett, who outlined the new school bus rule during a visit to a Deatsville, Ala., elementary school with that states governor, Bob Riley.

Admiral Barrett noted that a phone call from Gov. Riley to Secretary Peters following a November 2006 bus crash in Huntsville helped prompt the new rule. "The fact that there are so few fatalities on buses every year is little solace for a grieving parent or a saddened governor," Barrett said.

The rule, according to some USDOT officials, was not expected to be issued until early next year (see Aug. 15 Bus & Motorcoach News).