Recently, on a westbound Amtrak train between Sacramento and Davis, a young woman was feeling a little down on her luck. She had the cell phone out and was venting.

“No, I’m not driving it because the stupid Breathalyzer is broken, so I have to have it towed back to Circuit City by tonight,” she said into the phone. “People kept pulling over to help me, and they go, ‘Is that a Breathalyzer in your car?’”

Their interest piqued, the other nearby passengers listened, surreptitiously. She was in her early 20s and was dressed in a T-shirt, jeans and sporty sandals, with hair pulled into a stout ponytail, evidence of recent sun time on her freckled face, and a wearied look in her eyes.

“They’re like, ‘Did the court require that?’” she said. “I was like, ‘No.’ They were like, ‘What, did you get five DUIs?’ I said I got one. They’re like, ‘Can I try it?’ I was like, ‘No.’”

The ignition interlock device, or IID, prevents drivers from starting their vehicles without first providing an acceptable breath sample. At judges’ discretion, first-time DUI offenders may, as a condition of their probation, shorten their driver’s-license suspension by installing an IID, at their own expense. Critics say it’s too easy to fake an IID out—by driving a different car, for example, or by getting your passenger to provide the breath sample. But, as the young woman explained to her friend on the phone, its effectiveness as a deterrent is not negligible. For one thing, it can break. For another: “Imagine if you meet some guy, and you have Breathalyzer in your car,” she said. “It’s like, ‘Hang on, I just need to blow in my little tube before we can go anywhere.’”

She called herself embarrassed, but she seemed unconcerned with releasing her story to a train car full of strangers. As the conversation went on, and the train gently rocked its way through the valley’s flatlands, the young woman assumed an appealing air of caution-to-the-wind self-mockery. She giggled, recounting a talk with her mother.

“She says to me, ‘I’m glad that this happened to you.’ I’m like, ‘What?’ I get on the train, and she goes, ‘Don’t buy alcohol on the train.’”

After a few more calls—one to a sibling (“Did Mom tell you about the judge and how he hates me?”) and another, more procedural than conversational, to report a stolen credit card, listeners were left to piece together what must have been, on balance, a rotten weekend and to admire the young woman’s aplomb.

Eventually, she hung up and sat quietly for a while. The train whistle howled. A teenage acquaintance, who’d tried not to eavesdrop, and failed, watched her from across the aisle.

“I didn’t know they were allowed to serve alcohol on trains,” he said.

“They serve alcohol everywhere,” the young woman explained.