-- The National Highway Traffic Safety Administration has tentatively decided not to require automatic reversing windows, the agency said Friday.

In 2008, Congress required NHTSA to study whether to require power windows to reverse direction when they detect an obstruction, to prevent children from being trapped, injured, or killed.

But NHTSA says another regulation in place since last fall makes automatic reversing windows unnecessary.

"The agency has tentatively determined that the scope of the power window safety issue can be effectively addressed without mandating (automatic reversing systems) on all windows," NHTSA said in a draft regulation released today.

The NHTSA regulation that took effect in October 2008 required automakers to install window switches that users must pull up in order to open a window, but it does not require that windows reverse direction automatically when obstructed. That's to prevent people from accidentally rolling windows up.

NHTSA said "safer switches" are likely to prevent 50 to 75 percent of all power window-related fatalities

NHTSA said in its assessment that approximately six deaths and at least 1,955 injuries result annually from the operation of vehicle power window systems.

Most of the injuries are bruises, broken bones and others from children getting fingers or arms caught in windows.

Requiring windows to automatically reverse when they hit an obstruction would cost automakers $6 to $12 per window, according to NHTSA.

Although it is rare for power windows to kill children, it has happened. In December 2006, a 3-year-old girl was killed in a Pontiac Vibe in Detroit when she was caught in a window that rolled up and strangled her.

But NHTSA said one-touch switches for windows might pose a safety issue and proposed requiring the automatic reversing systems on those windows.

Nearly all of those one-touch window systems already have automatic-reversing requirements.

A study of the window issue was one of several required by the 2008 law. Earlier this year, NHTSA released a report that says mandatory cameras still aren't cost effective to prevent up to 300 backover deaths annually.

NHTSA estimated that, on average, there are 292 fatalities and 18,000 injuries -- 3,000 of which are judged to be incapacitating -- resulting from backovers every year. A large number are among small children and senior citizens.

The data show that pickup trucks (72 of 288) and SUVs (68 of 228) are responsible for a larger-than-proportional share of such injuries among vehicles in the U.S. fleet.

NHTSA said "the net cost per equivalent life saved for camera systems ranged from $13.8 (million) to $72.2 million," and for back-up sensors, it ranged from $11.3 (million) to $62.5 million.

"None of the systems are cost effective compared to our comprehensive cost estimate for a statistical life of $6.1 million," NHTSA's report said.