But car makers told regulators the guidelines also should include such portable devices as cellphones, GPS units and smartphones that motorists often are tempted to use while driving.
"It does seem likely that drivers will use other devices not subject to the guidelines," said Mike Cammisa, director of safety for Global Automakers, which represents General Motors, Ford, Chrysler, Honda, Toyota and other global automakers and original equipment manufacturers.
"We need to make sure to get this right, it's important to recognize that overly restrictive limits on in-vehicle devices could result in greater distraction as drivers substitute hand-held devices for those functions integrated into the vehicle, diminishing the effectiveness of the guidelines."
"Distracted driving is unsafe, irresponsible and can have deadly consequences," NHTSA Administrator David Strickland said Monday at the first of three hearings held last week in Washington, Chicago and Los Angeles.
In December, the National Transportation Safety Board recommended states ban all use of portable cellphones -- including hands-free devices -- while driving. Some onboard cellular devices built-into vehicles like GM's OnStar and Ford's voice-activated Sync -- which can report emergencies -- would be permitted. In-dash MyFordTouch systems disable some tasks such as typing in addresses while the vehicle is in gear.
Tom Bolonga, vice president of engineering of BMW North America, said he was concerned about aftermarket accessories and portable mobile devices, including some that actually allow a driver to watch television while in motion.
Talk about distracting.
Strickland said his agency was considering a request by automakers to examine studies NHTSA used to formulate its guidelines and car companies requested 60 days for comment before the proposals are made official, The Detroit News said.
Concerned about distracted drivers, 35 U.S. states have banned texting behind the wheel and 10 states and scores of local communities have outlawed use of hand-held cell phones by drivers, the Insurance Institute for Highway Safety said.
NHTSA's Strickland gives this rationale for the guidelines: "People have an intrinsic trust in their own ability to drive," he said. "Everyone else stinks -- I'm a fantastic driver. I can manage these additional tasks. We need to convey to people that you are not special."
NHTSA cited 2010 crash data that indicated 17 percent of crashes reported to police involved driver distraction, but only 3 percent of those crashes involved use of in-car onboard devices.
Rearview car cameras
Supporters of rearview cameras in vehicles say the devices can prevent tragedies caused by drivers not seeing what's behind their cars, pickups and sport-utility vehicles when in reverse.
Everyone who drives knows mirrors only cover so much viewing area and the larger the vehicle, the bigger the blind spots, especially directly behind when backing up.
"Every vehicle has a blind spot immediately behind the rear bumper. It can be five feet or 50 feet, depending on the car's styling. Lost in that space might be a fire hydrant, a pet, or even a child," said a policy statement by the non-profit Consumers Union, publishers of Consumer Reports.
U.S. Transportation Secretary Ray Lahood has delayed until later this year a final rule on mandating rearview cameras on all passenger vehicles, but he said "significant progress" had been made.
"Further study and data analysis -- including of a wider range of vehicles and drivers -- is important to ensure the most protective and efficient rule possible," Lahood said in a statement in late February. "The department remains committed to improving rearview visibility for the nation's fleet and we expect to complete our work and issue a final rule by Dec. 31, 2012."
Nearly 230 deaths each year and as many as 18,000 injuries are blamed on drivers who fail to see pedestrians behind them when they are in reverse. NHTSA estimates it would cost about $200 per vehicle to build in a rearview video camera -- an estimated $1.9 billion to $2.7 billion cost for automakers that no doubt would be at least partly passed on to buyers, The New York Times said.
The cost of adding a camera would be cheaper if a model already comes equipped with a display screen.
About 45 percent of 2012 vehicles are equipped with a rearview camera that shows an image on a computer monitor-style screen when the driver shifts into reverse. Some luxury vehicles put small video monitors inside the rearview mirror.
"This is one thing we can and should do," said Clarence Ditlow, executive director of the Center for Auto Safety in Washington. "In terms of absolute numbers of lives saved, it certainly isn't the highest. But in terms of emotional tragedy … when you have a parent that kills a child in an incident that's utterly avoidable, they don't ever forget it."
NHTSA originally proposed phasing in a requirement for rearview cameras in vehicles by the 2014 model year, but efforts to set a standard for camera response times and create a rule have been extended several times.
Federal safety regulators have expanded an investigation into complaints of throttles sticking in 2001 through 2006 Ford Taurus and Mercury Sable models.
The National Highway Traffic Safety Administration last week added 1.56 million more Ford passenger cars to its inquiry, bringing the total to 1.92 million cars.
"The agency is actively investigating a potential issue with a struck throttle resulting from cruise control cable detachment involving certain Ford vehicles," NHTSA spokeswoman Lynda Tran told The Detroit News.
A preliminary investigation was opened after NHTSA reported it had received 14 complaints from Taurus owners who said the engine accelerated as high as 4,000 RPMs after the car was shifted into neutral or park. No crashes or injuries were reported due to the revving, but one car zipped through a red light and was halfway into an intersection before the driver was able to stop, the Detroit Free Press said.
Ford is cooperating with the investigation.
"We're aware of the NHTSA investigation and as always we will cooperate fully with the agency," a spokesman said.
Mazda cuts jobs in Europe, restructures
Hurt by sagging sales, Japanese automaker Mazda last week said it would cut the number of employees at its European headquarters and restructure operations because of the "difficult global situation."
Automotive News Europe said the workforce at the European offices in Leverkusen, Germany, would be reduced from 306 employees to 109. Mazda's European headquarters has responsibility for 22 national sales companies in the European Union, Switzerland, Norway, Turkey and Russia.
The German sales operation is not affected by the changes, Automotive News Europe said.
Although its European operations remain profitable, Mazda, which builds its vehicles in Japan, Thailand and a joint venture Auto Alliance plant in Michigan, has been impacted by the strong yen and last month said it expected its biggest global loss in 11 years, $1.2 billion, for the fiscal year ending March 31.
Mazda Europe President Jeffrey Guyton said new products -- like the high-tech CX-5 compact crossover utility vehicle being introduced in the United States and Europe -- would spur interest and sales. Mazda expects to sell 40,000 CX-5s in Europe in the next year and has already sold 8,000 in Japan. A new Mazda6 sedan is to be introduced at September's Paris auto show, Automotive News Europe reported.