Last spring, Aimee Witteman bought an electric cargo bike. The fateful purchase, she says, changed her life.

A fervent cyclist in her younger years, the south Minneapolis mom found it increasingly difficult to find time to bike after having two daughters, now ages six and three. Plus, she has a full-time job leading the climate change program at the McKnight Foundation. Her busy life involved frequent schleps here and there — usually in a car that was on its "last legs."

Since May, Witteman has biked about 1,000 miles around town on her Surly Big Easy cargo bike with ample space for her kids. She's part of a growing movement of families — particularly moms — looking to curtail the drudgery of commuting and endless errand-running, all the while minimizing their impact on the planet.

"I'm not emitting carbon, I'm getting exercise. I put my ear phones on when I'm on the bike trail and I'm jamming out to Beyoncé," said Witteman, 42. "It's like an antidote to a midlife crisis. It's my version of a Corvette."

The kids, she adds, love it.

Witteman's bike, which cost about $5,000, has a long tail that gives her enough room to pack up the kids for runs to the grocery store, the park, school, the bus stop and work in downtown Minneapolis. The electric assist is available to help haul the load without getting sweaty or tuckered out.

On Thursday, Twin Cities cargo bike enthusiasts (and others) will converge on the Riverview Theater in Minneapolis for a documentary called "Motherload," a labor of love for California-based filmmaker Liz Canning. The crowdsourced film details Canning's quest as a new mother "to understand the increasing isolation and disconnection of the digital age, its planetary impact, and how cargo bikes could be an antidote."

The film, which was funded and distributed in part by fellow cargo bike enthusiasts, comes at a time when sales of E-bikes are booming across the country. According to the Bicycle Product Suppliers Association, a Colorado-based trade organization, sales of the bikes have more than tripled from $43 million in 2016 to $143 million last year.

The group doesn't break out sales for cargo bikes, electric or otherwise. But Luke Breen, owner of Perennial Cycle in Minneapolis, says the popularity of all kinds of cargo bikes is "huge, it's a big part of our business. Ten years ago cargo bikes were zero percent of our business." (He declined to provide exact sales figures.)

Breen attributes the boost in cargo bike sales to families that want to ditch their cars altogether, or go "car light" — meaning they want to own just one car, or drive less frequently.

"There's really a lack of imagination around bicycles in this country," Canning said. "People see them as a toy that you ride when you're little, and then give up. We really want to emphasize that it's a tool that can do so much more."

The most popular cargo bike at Perennial Cycle is the Spicy Curry E-bike by Yuba, which has a $4,500 price tag, which may seem financially daunting. But, Breen says, if a cargo bike is considered a means of transportation, it's actually quite affordable when compared to the cost of keeping a car. The average cost to own a car is $9,282 a year, or $773.50 a month, according to AAA.

Cargo bikes, which originated in the Netherlands as a workhorse means of transport for food delivery, have long been popular abroad. But now they're starting to take hold in the United States, particularly in bike-friendly places such as Portland, Ore. — and the Twin Cities.

Witteman says Minneapolis' network of bike-only thoroughfares and dedicated bike lanes is key to making her cargo-bike lifestyle work, and safe. Although Canning's film documents women experiencing "bike lash" from inexplicably angry motorists, Witteman says she hasn't experienced any negative feedback.

In fact, the reaction to her lifestyle choice is quite the opposite.

"It's not only great to be outside with your kids, you're role-modeling as a new way to get around," she said. "You're getting exercise, and you feel the sun on your face, which is hard to get when you're working."

Witteman concedes the impending winter in Minnesota may prove to be a challenge, particularly since road salt could erode her beloved two-wheeled commuter.

"I'll have to see if it's doable," she said. But she's ready to give it a try.

Janet Moore • 612-673-7752 @ByJanetMoore