He's cruising along, sipping his Big Gulp, chatting on the cell phone with a friend, snatching the occasional french fry from the greasy fast food bag riding shotgun, when something unexpected happens.

An E-mail arrives from the office, and he learns that the deadline for a 200-page report he has yet to write has just been moved up. It's due now in three days. A panic attack ensues as he hangs up the phone.

That raises a serious question: Do we really need more potentially panic-inducing stimuli for the guy behind the wheel?

It's an issue of great debate in the auto industry, which wants to promote safe vehicle operation while satisfying the growing urge for Americans who love to "multi-task" behind the wheel.

It all started with the cell phone, which was bolstered not only by functionality but also by the perceived status that it spawned. For many people, cell phones and pagers have created a new era in which cars and trucks are an extension of the home or office, a convenient merging of the Information Age and the passion for mobility.

And automakers see that as an opportunity to sell even more electronic gadgets, from navigation systems and on-board vehicle computers with Internet and E-mail access to televisions for rear-seat passengers.

A recent report by the National Highway Traffic Safety Administration, however, suggests that cell phones and other wireless gizmos are distractions that only serve to increase a driver's risk on the highways.

A study reported last year in the New England Journal of Medicine concludes that drivers are 4.3 times more likely to have an accident while talking on portable phones. Researchers say the increased risk is "similar to the hazard associated with driving with a blood alcohol level at the legal limit."

NHTSA concedes that cell phones are great for improved personal security, for getting quick help for a stranded or injured motorist and for communicating traffic information.

But the federal agency also notes that previous studies by the agency have found that driver inattention is a primary or contributing factor in up to 50% of all crashes.

Overall, the report was inconclusive in estimating the magnitude of the distractions with regard to wireless communication. Research continues.

Studying the effects of cell phones is not difficult, as their numbers have grown from 345,000 in 1985 to 50 million today. That number is expected to more than double by the year 2000. But figuring out how drivers will interact with E-mail and the Internet is a little hard when vehicles are not yet equipped with them.

"There's a lot of human research that hasn't been done because we don't have these systems yet," says Stephen Kratzke, director of NHTSA's Office of Crash Avoidance Standards.

Part of the agency's research is an initiative by the Society of Automotive Engineers and the Big Three to determine the best way to prevent driver overload.

Before its late-winter International Congress and Exhibition in Detroit, the SAE announced that it will draft voluntary guidelines for manufacturing and installing these advanced communication tools.

The challenge for suppliers developing these devices is to make them easy to operate. To make them safer, there's a big push for them to be "hands-free" and solely voice-activated.

"Do you really want Internet access while you're driving, and if so do you want to look at the text while you're driving? I certainly don't," says Mal Hollombe, vice president of sales and marketing for IVS Inc., an electronics joint venture between Amerigon and Yazaki Corp.

Based in Monrovia, CA, IVS has developed Avstar, a vehicle navigation device that plugs into the cigarette lighter and operates solely by giving voice commands. There's no buttons to push and no screen to see, although a screen is available for an extra $300.

"I drive 54 miles (86 km) each day to work," Mr. Hollombe says, "and I know people are causing accidents by being distracted on the phone because I see them."

Avstar will sell for $1,000 without Global Positioning System (GPS) capability and $1,349 with GPS when the product becomes available at deal-erships in June. There's also a fee of between $39 and $89 to activate each map for the 24 U.S. cities included on four CD-roms. IVS hopes to have the product in retail outlets by year's end.

"The fewer distractions there are visible in a vehicle, the safer it will be on the road," Mr. Hollombe says.

Despite concerns about potential hazards, the truth is that most people who multi-task on the road do so without any problems or accidents.

"People are already doing stuff in their vehicles with electronics. They're checking pages, dialing cell phones," says Brian McCalley, marketing manager of intelligent transportation systems with Motorola's Transportation Systems Group in Austin, TX.

"People are so used to using electronics outside the vehicle that it's a natural extension for them to do it in a car. I don't think it's quite an issue for certain demographics," Mr. McCalley says.

"I think people would like to do more things in their vehicles. If I can check my E-mail, what's the difference between that and listening to the radio?" For Motorola, which supplies automotive semiconductors and wireless technology, the convergence of transportation and information provides a market with huge growth potential.

Motorola is developing a central communication display on the instrument panel where a driver could control numerous vehicle functions from a menu, including navigation, climate control, stereo, paging, Internet access and emergency call service.

Mr. McCalley says it's not necessary for all functions to be voice-activated. Drivers are used to pushing buttons and will remain comfortable with it as long as future systems are simple, he says. Besides, voice-activated systems are far from being perfected, or affordable.

"It all depends on how well the information is presented to the driver, and how easy it is to get that information. If you have to struggle to get that information, it won't do much," Mr. McCalley says.

The Big Three already have learned a costly lesson about rushing to market with new technology that isn't user-friendly.

In 1987, Ronald Knockeart bought a brand new Lincoln Continental with a "state-of-the-art" driver information system that included more than a dozen buttons controlling myriad vehicle functions.

"It was so complicated you needed a manual," says Mr. Knockeart, vice president of intelligent transportation systems for electronics giant Siemens Automotive.

"I'm a technical guy, and we make equipment like this and use it. But this system was overpowering in the things you had to do. It was very distracting," he says. "It didn't take long for the car companies to figure out that people didn't like it."

Today, menus are still offered, but they are simpler to use and less meddlesome. "Distractions are recognized by the industry already as an area we'd better pay attention to," Mr. Knockeart says.

Siemens has developed three navigation systems and is able to provide an Internet link as well. One method that Siemens is considering to prevent distractions is to allow Internet access only when the vehicle is in park.

"I don't think there will be any government study that says which is the best way to do it," says Mr. Knockeart. "It's all so new and evolving that users and companies developing it will have to figure it out."

Several suppliers are investing heavily in the future of in-vehicle communications. Among them: United Technologies Automotive, Visteon Automotive Systems, Delphi Automotive Systems and Mannesmann VDO, which recently acquired the business of Philips Car Systems and Philips Automotive Electronics.

At the SAE Congress, Visteon demonstrated a prototype of its Information, Communication, Entertainment, Safety and Security (ICES) system, which will be available later this year on the aftermarket. It offers E-mail and Internet access.

When asked about the potential distractions associated with the new gadgets, Visteon President Charles Szuluk says safety should not be a problem because ICES is voice activated.

"You don't need to take your eyes off the road," he says. Let's hope not.