U.S. Transportation Secretary Mary Peters doesn't hesitate when asked her worst day in office. She was home in her native Arizona last Aug. 1 when she got the jarring phone call from Washington.

The eight-lane Interstate 35 bridge near downtown Minneapolis had collapsed, hurtling cars, drivers and passengers into the Mississippi River. Thirteen died; 145 were injured. News channels were broadcasting video of concrete slabs buckling and disappearing into the abyss. Overlooking the scene the next morning, she struggled to absorb the disaster.

"I was absolutely sick," she recalls. "I wondered, 'How did it fail? Will others fail?' It was crushing."

As Cabinet positions go, running the Department of Transportation typically is not a high-visibility job. But a stream of events, and Peters' own drive, have kept her in the spotlight since she took the job 16 months ago. In the last six months alone, she has confronted the Minneapolis bridge collapse, charges of a dangerous shortage of air traffic controllers and the most onerous airline flight delays on record.

It's heady stuff for a plain-spoken and slightly unorthodox Harley-Davidson-riding Republican who first came to Washington six years ago to run the Federal Highway Administration. Peters, 59, now leads a Cabinet agency with 60,000 workers and a $70 billion budget.

Her rise is even more remarkable for her past: a determined climb out of a working-class life that could have been a dead end.

Mary Elizabeth Peters' parents divorced when she was 6, and her father raised four children in Phoenix. At 17, Peters wed boyfriend Terry Peters, a Marine as her father had been. By the time she was 30, they had three kids and were living in his hometown of Logansport, Ind. The biggest employer was a meatpacking plant, Wilson Foods. She and Terry applied.

The unionized plant paid $10 an hour, a lot for a factory job in 1980. To make that, she had to perform the same grisly, physically demanding work as the men did on the kill floor where hogs were stunned with an electric prod, bled out and cut up for packaging.

"It was very, very hard work, a dangerous occupation," she says. She still has scars where knives missed their mark.

Her son Terry Jr., now the Seattle manager for a payroll processing firm, says his mother's success has surprised even him. But, he says, "She is one of the hardest-working people I have ever come across. I'm only 35. She gets up earlier and stays up later than I do."

Terry Jr. says his mother rises early to work out in the gym and listens to Bruce Springsteen on her iPod. He says people are surprised when they learn how down-to-earth she is. "People have this perception that we are this privileged family, until they get to know us."

Husband Terry Peters, semi-retired and living in suburban Phoenix, declined an interview request. Mary Peters said they commute between Washington and Phoenix so he can live near their children and grandchildren.

Life in Logansport was a formative time for Peters. She became a union steward at Wilson Foods and was active in workplace safety issues. When the company asked the union to accept pay cuts so it could stay competitive with non-union meatpackers, the union leaders refused and called a strike. Peters was dismayed; she thought the union should have opened negotiations with the company.

The strike dragged on for weeks while employees got meager strike pay from the union. Wilson Foods filed for Chapter 11 bankruptcy reorganization and slashed pay in bankruptcy court. When the strike ended, employees went back to work making 40% less than they had before.

"Some people lost their homes, their cars," she says. "It was devastating."

A new start

The couple moved back to her native Phoenix to look for new jobs. Mary Peters had come of age in the era of Arizona Republican Barry Goldwater, making her receptive to his conservative message. Her disillusionment with union leaders at the Wilson plant pushed her solidly into the Republican camp.

Seeking stability after the turmoil in Indiana, Peters took a job in 1985 as a secretary at the Arizona Department of Transportation. Arizona's population was exploding, and the state was building freeways as fast as it could pour concrete.

She worked hard and got noticed. She took evening and weekend courses to earn a bachelor's degree in management from the University of Phoenix.

Several promotions later, then-Gov. Jane Hull, a Republican and early supporter of Texas Gov. George Bush's bid for the White House, named Peters the first female director of the Arizona DOT. Hull says she chose Peters in part because of her popularity with fellow ADOT employees. "She got very high marks from them," Hull says. "I think it's because she levels with people."

After Bush took office in 2001, Peters was at her office in Phoenix one day when her secretary said the White House was calling. Peters thought it was a prank. Bush wanted her to interview for the job running the Federal Highway Administration, which has the DOT's biggest budget.

On Sept. 11, before her appointment had been confirmed by the Senate, terrorists struck New York and Washington.

Her daughters, Tammy and Tina, called her from Arizona, terrified. "They said, 'Come home now,' " Peters recalls. She stayed out of a sense of duty. She wondered immediately what landmarks under her jurisdiction — San Francisco's Golden Gate Bridge for example — might be targeted.

"We identified infrastructure that might be vulnerable," she says.

Four years later, Peters left Washington to be closer to her family in Phoenix. She joined engineering firm HDR as national director for transportation policy, and began building a consulting business. Some Arizona Republicans urged her to run for governor in 2006, but she declined. Hull says Peters would make a "very good" candidate for governor in 2010. Although Peters is mum on that, she does say she wants to remain in public service after President Bush leaves office next January.

When former DOT secretary Norman Mineta resigned as secretary in 2006, the White House called again, asking Peters to interview for the job.

Stepping into Mineta's shoes hasn't been easy, Peters says. In a recent speech in Washington, she said measuring up to Mineta, who was in Congress for 20 years and chaired the House Transportation Committee, sometimes makes her feel like Ginger Rogers trying to keep up with Fred Astaire. "I have to dance backward and in high heels," she joked.

She has been to Minneapolis four times since the bridge collapsed to survey the damage and reassure local and state officials.

"I needed to get out there," she says. "One of the first things I did was tell the states to inspect similar bridges."

The National Transportation Safety Board, DOT's accident investigation arm, has said the 40-year-old bridge was at risk from the beginning because of a design flaw. The full cause of the collapse is still under investigation. It's controversial: Rep. Jim Oberstar, D-Minn., and Minneapolis Mayor R.T. Rybak, for example, want to know whether corrosion, inadequate inspections or other factors contributed to the catastrophe.

But Rybak, a Democrat, can't praise Peters enough for her help after the accident. "She was focused, completely accessible and tough when she had to be," said Rybak. "It meant a lot to me in the middle of a crisis to pick up the phone and not only get someone in Washington, but get something done."

When Rybak needed $2 million to pay emergency traffic officers, for example, Peters helped Minneapolis get federal funding, he said.

Given Peters' background in bridges and roads, the complexities of the airline industry and the air-traffic control system have presented the steepest learning curve. Reviews are mixed.

Jim May, head of the Air Transport Association, the airlines' Washington-based trade group, says Peters has learned as quickly as anyone could, considering she was "thrust into a situation with intractable issues and (with) people banging on you from all sides."

Says May: "She's doing a very credible job, but that doesn't mean I agree with her."

In fact, the ATA has threatened to sue the DOT if it follows through on a proposal to make airlines pay more to fly in and out of New York John F. Kennedy and Newark Liberty airports at the busiest times. "Congestion pricing," it's called.

Peters says that would reduce chronic flight delays during peak times. Airlines argue the government doesn't have the legal authority to do it, and say Peters is pushing a political agenda of conservatives who believe market forces work better than regulation.

In December, the DOT and the FAA did succeed in persuading airlines to voluntarily reduce the number of flights per hour at Kennedy and Newark to ease extraordinary flight delays there, especially in bad weather.

"Summer was horrible," Peters says. "Passengers were missing funerals, weddings. Everyone had (flight delay) horror stories. … We needed to do something."

Peters and the FAA told the airlines to cut back their New York flight schedules or the government would. The airlines blinked first.

"That's more than we're used to seeing from the Democrats," says former DOT Inspector General Ken Mead. "You have to give her credit."

But Peters so far has been unable to mend a deep divide between the FAA's management and the union representing air-traffic controllers. Senior controllers are retiring in large numbers, prompting fears of a critical shortage at busy airports. The FAA says hiring will keep up with retirements.

Controllers don't have the right to strike, but they are chafing under an unpopular labor contract imposed in 2006 when negotiations fell apart. Union leaders say too many controllers are working six-day weeks, risking mistakes. "I was so hopeful she would clear up what's going on," says union President Patrick Forrey. Through a spokesperson, Peters said only that she remains optimistic.

Safety in mind

Safety is one of Peters' top goals, a holdover from her days at the meatpacking plant. She frets that alcohol-related driving deaths have stopped declining. Of personal concern is the fact that motorcycle deaths in 2006 rose for the ninth-straight year, to 4,810. Only 20 states and the District of Columbia require motorcycle helmets.

Husband Terry has long ridden a Harley-Davidson motorcycle for fun and years ago, persuaded Mary to try it. They enjoy riding together.

She recently strapped on her black helmet and leather riding gear and recorded a TV public-service announcement warning motorcyclists to be careful. She speaks from painful experience: She broke her collarbone when she and Terry collided while riding in 2005.

Asked why she rides, she allows a glimpse into what drives her.

"It's the freedom of the road," she says. "Because you can experience the wind and weather, and because it's a little dangerous."