Getting directions on the road from Google Maps and other smartphone apps is a popular alternative to the expensive navigation aids included in some cars.

The apps are also a gray area when it comes to laws banning the use of cellphones or texting while driving.

The Transportation Department wants to enter the argument.

The department is intensifying its battle against distracted driving by seeking explicit authority from Congress to regulate navigation aids of all types, including apps on smartphones.

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The measure, included in the Obama administration’s proposed transportation bill, would specify that the National Highway Traffic Safety Administration (NHTSA) has the authority to set restrictions on the apps, and later order changes if they are deemed dangerous, much the way it currently regulates mechanical features of cars.

The measure has the support of automakers, which already mostly comply with voluntary guidelines for built-in navigation systems, but it has run into stiff opposition from technology companies, which say that any such law would be impractical and impossible to enforce.

It’s another example, they say, of federal regulators trying vainly to keep up with a rapidly changing industry.

“They don’t have enough software engineers,” said Catherine McCullough, executive director of the Intelligent Car Coalition, an industry group. “They don’t have the budget or the structure to oversee both Silicon Valley and the auto industry.”

The underlying issue has already worked its way into the courts. In California, Steven Spriggs received a $165 ticket two years ago for using his iPhone while driving in stop-and-go traffic near Fresno.

A highway patrol motorcycle officer rolled up alongside his car after seeing the glow from the screen on Spriggs’ face.

“I held it up and said, ‘It’s a map,’ ” Spriggs said.

He was not talking on the phone, which is barred by California law.

But the police officer would not budge. “He said, ‘Pull over, it doesn’t matter,’ ” said Spriggs, the director of planned giving at California State University, Fresno.

An appeals court ruled this year that it did matter, and Spriggs’ conviction was reversed.

Regulators maintain that they already have the authority over navigation aids and merely want it clearly written into law.

Twice last year, David Strickland, when he was administrator of NHTSA, told Congress that navigation systems could be “classified as motor-vehicle equipment.”

The electronics industry, in response, argues that “motor vehicle equipment” includes objects like key-chain fobs that can unlock a car by remote control, not apps on a smartphone.

Regulators are making the push as navigation apps are proliferating and increasing in sophistication.

While most smartphone users are familiar with such straightforward navigation aids as Google Maps, Waze relies on a social network of users to report road conditions, hazards and the presence of police cars in real time. Wazers, as users are known, earn points the more they contribute and gain status in the community.

But Waze’s user agreement contains a warning that says, in part, “Sending traffic updates and text messages to the service while you drive is strictly prohibited.”

And the app’s interface is meant to prevent a report while the car is in motion, unless the user hits a button saying a passenger is making the entry.

Despite the warning, there is nothing to prevent a driver from hitting the passenger button. Waze, which Google bought last year, declined to comment.

Safety advocates say regulators need to do more.

“We absolutely need to be looking at these nomadic devices,” said Deborah Hersman, president of the National Safety Council, a nonprofit group chartered by Congress, and a former chairwoman of the National Transportation Safety Board.