NHTSA "satisfied" with safety changes for GM's Volt

The National Highway Traffic Safety Administration believes changes proposed by General Motors to its Chevrolet Volt will help prevent future battery fires.

NHTSA Administrator David Strickland told reporters during the Detroit Auto Show last week that the agency was "comfortable" with GM's fixes even though its investigation remained open. The NHTSA began investigating the case in November after revealing that Volt batteries had caught fire days or weeks after being damaged in crash tests.

GM now says it will add steel reinforcements around the battery of the plug-in car to for added protection in crashes. It also will install a monitor to detect any coolant leaks -- believed to be the source of the fires. GM says it staged four new crash tests in December with the changes in place and that no coolant leaks resulted.

Publicity about the fires apparently has not deterred buyers: The company sold 1,529 Volts in December, more than any previous month even though the 7,671 sold for all of 2011 fell short of GM's 10,000 goal. Buyers may have been reassured by NHTSA's own award of the maximum five stars to the Volt in its crash test and safety ratings.

In other Detroit conversations with reporters, Strickland says the agency may make changes to those star ratings to give additional emphasis to new technologies that help avoid crashes in the first place. NHTSA seems pleased with its past promotion of electronic stability control, which helps avoid rollover accidents. That technology is now required on all 2012 and later models.

New systems that may figure in NHTSA ratings include the so-called drowsy driver alert, which sounds an alarm or vibrates the steering wheel if a car is drifting into another lane. And smart cruise control measures how fast a car is coming up on another vehicle in front of it and starts applying the brakes if a crash seems imminent.