Traffic and "The Starbuck's Effect"

Almost every morning for a decade, Roger Bratter has stopped at a Starbucks in Gaithersburg to sip a grande latte sans foam or a green tea and spend 20 peaceful minutes with the newspaper before heading to his auto repair shop.

Grabbing a cup at home, he said, just isn't the same.

"Our kid's got to go to school. My wife has to get to the Metro. I've got to get to work," Bratter, 54, said during a 7:30 a.m. visit last week. "If I have to make [coffee] and clean it up, it's just an extra stress factor."

Minutes earlier, at the same Starbucks on Quince Orchard Road, Steve Elgin, 41, pulled into the drive-through. A venti latte once or twice a week takes the edge off his one-hour commute between Frederick and Gaithersburg.

"It gives me something to do on [Interstate] 270," said Elgin, an executive in an insurance claims company.

The two men represent what one researcher says is evidence that the national craving for gourmet coffee may be adding mileage to the morning rush hour. And the numbers might be significant enough to complicate efforts to reduce traffic congestion, save fuel and reduce air pollution.

She calls it -- what else? -- the "Starbucks Effect."

"If you see people replacing an in-home activity like brewing your own coffee with an activity that requires a new [car] trip, that's not exactly the trend we're looking for," said Nancy McGuckin, a travel behavior analyst who used U.S. Department of Transportation data to develop her findings.

McGuckin built her thesis from the department's National Household Travel Survey, a periodic study of about 70,000 households in which each member keeps a diary of comings and goings -- who's driving where, how far and for what purpose.

What McGuckin and two colleagues found in comparing the 1995 and 2001 surveys, the two most recent ones, was that 1.6 million new more Americans tacked personal errands onto their commutes. Studies have long shown that errands are an integral part of the daily routine, especially on the way home from work, when arrival times are more flexible. Women continue to outpace men in these trips, shouldering most of the early-evening family tasks after leaving the office, such as grocery shopping and picking up children.