WASHINGTON, DC — The National Highway Traffic Safety Admin. (NHTSA) is at a loss for words over a key element of its driver distraction research.

Why? Researchers don't know what to talk about, the agency tells a Society of Automotive Engineers (SAE) meeting.

Intent on studying the effects of cell phone use on driver performance, NHTSA must recreate — as close as possible — real-world conditions. Complete with emotional stress.

However, while the National Advanced Driving Simulator (NADS) offers safety for the subject in surroundings that are easy to monitor, it doesn't provide them with “compelling” conversation. Say, something along the lines of heated business negotiations. Or that call from your doctor advising you to make an appointment — soon.

Researchers, therefore, must become silver-tongued devils. Problem is, they're tongue-tied, NHTSA reveals.

W. Riley Garrott, chief of NHTSA's vehicle stability and control division, doesn't mince words when he describes the impasse. “It's going to be with us for awhile,” he says.

Not even the smoothest talker, it seems, is up to the task of unnerving test drivers because — despite the simulator's effectiveness — they know the exercise is a ruse.

“We thought of having the driver's wife call him,” one researcher says before falling silent, apparently shocking herself at such a prospect.

Transport Canada already has been down this road. NHTSA's northern counterpart removed passion from the equation in favor of pragmatism.

“We use arithmetic questions,” says Ottawa's leading ergonomist, Ian Noy. By increasing their complexity, he adds, “we sort of manipulate the difficulty of the conversation, if you will.”

Regardless, Mr. Noy says, getting inside a test driver's helmet could threaten a researcher's objectivity.

“If you start to think about situations that could potentially be emotional, it presents a lot of ethical questions. … You can't engage somebody in an emotional conversation without becoming personal about it. And that becomes a real issue.”

Nevertheless, NHTSA has not given up on finding some way to start a war of words behind the wheel.

“You can't,” Mr. Garrott says, adding in-depth conversation is a “fundamental” factor influencing driver behavior.

Evidenced by the standing-room-only crowd of SAE attendees who took in NHTSA's methodology update, few dispute the urgency of coming to grips with driver distraction.

Those in attendance heard that a NHTSA survey scheduled for release this summer finds 54% of motorists in the U.S. have access to cell phones while they're on the road.

Of these, 73% say they've talked on their phones while driving. And driver distraction — from cell phones and other causes — is a contributing factor in 20% to 30% of all motor vehicle crashes.

Meanwhile, preliminary results of NHTSA's device-related distraction measurement study show performing a secondary task while driving reduces optimum driving performance by 15%. And of seven behaviors tested, the most detrimental was list writing, which reduced performance by 25%. Others, from the highest-risk to the lowest were:

  • Navigation system data entry (18%)
  • CD changing (17%)
  • Reading (16%)
  • Grooming/eating and counting (both 12%)
  • Phone dialing (8%)

On the research front, NHTSA has grouped driver distraction methodologies using a kind of best-practices model. It calls for:

  • Real-world observations to determine driver propensity toward distracting activities and to evaluate any resulting errors;

  • Real-world road experiments to aid understanding of distraction potential in routine driving situations;

  • Closed-course experiments to aid understanding of distraction potential in routine and near-critical situations.

  • Simulator use, which lends itself to studying near-critical and critical situations.

The SAE meeting also reveals just how testy federal regulators are these days. And that doesn't just describe their relationship with the auto industry.

The driver distraction presentation was among no fewer than 10 progress reports on proposed product rating systems and future testing procedures.

With automotive engineers in a fishbowl because of industry concerns over cost and safety, the resulting undercurrent of uncertainty sparks healthy debate. Just ask Mr. Garrott, a respected veteran researcher affectionately known as “Rollover Riley.”

Meeting delegates grill him about the nuances of a proposed rollover rating system based not on static vehicle dimensions, but on dynamic driving tests.

No, test surface temperatures have not been monitored daily, he admits.

No, tires destined for test vehicles are not warehoused under climate-controlled conditions.

Yes, there have been “problems with tire shoulder wear” on test vehicles. But no, it has not been decided how much testing should be done before the tires are changed.

NHTSA will call for comments this summer on its proposed methodology. Deadline for devising the test: Fall 2002.