Electric scooters are flooding cities across the country, and a few suburbs right here in Massachusetts.
But as their numbers grow, so does the controversy around how to safely regulate a new mode of transportation.
Dockless rental scooters offered by companies such as Bird and Lime have rapidly transformed the streetscape in cities like Los Angeles and Washington, D.C., where tourists and commuters alike have embraced them, zipping down streets and sidewalks at speeds up to 15 miles per hour.
Advocates say electric scooters are one solution to the traffic congestion that plagues many major cities, offering a form of "micro-mobility" that can take more cars off the road.
But e-scooters have also received a lukewarm reception in many communities, as inexperienced riders collide with pedestrians and cyclists, weave in and out of traffic and leave scooters parked haphazardly on the sidewalk.
The debate over e-scooters will soon play out in Boston, where leaders are weighing the parameters of a new pilot program. The City Council approved the concept in March, though officials have been slow to get scooters rolling. A councilor told the NBC10 Boston Investigators there's no big story behind the delay — the committee crafting the pilot just hasn't gotten around to meeting.
With major ramifications for public safety, some say that might be a good thing.
Brookline launched the state's first electric scooter pilot in April. Resident Kim Smith was among the first to give the scooters a whirl.
"I thought, what harm could be done?" she said.
But a few moments later, she was lying on the ground, bleeding from her face. Smith said she looked for a brake and couldn't find one when she jumped on one of the new electric scooters in Brookline. She tumbled to the ground, whacking her head and face-planting on the pavement.
"It was very bloody," she said. "I had a lot of pain in my neck."
Her fall captured national attention, just as the debate over how to safely regulate electric scooters heats up.
Detractors point to scooter scofflaws — people riding with kids, kids riding alone, double riders, riders going against traffic. One viral video even captured a scooter rider cruising down the highway in Texas. All are violations of the scooter companies' rules and municipal laws.
And because many of the scooter programs don't require that you dock the devices anywhere in particular, many are left to block sidewalks and even handicap access ramps at the end of the curb. The backlash has spawned a range of social media accounts dedicated to their demise.
In Brookline, Selectwoman Heather Hamilton says it's hard to put the genie back in the bottle. Hamilton, a transportation planning professional, pushed hard for Brookline to launch its pilot. She said demand has been high, with the community logging about 130,000 e-scooter trips in less than six months.
"I see a great deal of potential," she said.
But there have been bumps in the road. Brookline police documented at least half a dozen crashes and officers have made hundreds of scooter stops for improper riding.
On the border with Boston, it didn't take long for the NBC10 Boston Investigators to spot half a dozen scooters that were chucked into the muck of the muddy river.
Brookline's pilot brought 300 scooters to an area of about 7 square miles. In a city the size of Boston, there could be thousands of scooters competing for space on already crowded roads and sidewalks.
Beyond the irritation, scooters have also been under scrutiny for a series of high-profile injuries and even some deaths. The Associated Press recently reported at least a dozen people have been killed in crashes linked to scooters nationwide.
A recent study of e-scooter use in Austin, Texas, found rider inexperience was a common factor in many crashes. Researchers there identified 190 people who were hurt while riding scooters over a period of roughly two months. They found about one in three was riding an e-scooter for the first time.
Riders use a mobile phone application to rent scooters and pay for trips, which are often $2 or less. Many apps also provide information on how to safely ride a scooter, though riders don't need to complete a course before they hop on.
Another common thread in the Texas study: Many injured riders weren't wearing helmets. The study found about 45 percent of riders who wound up in the emergency room suffered head injuries, and about 15 percent of those were categorized as traumatic brain injuries.
The scooter companies operating in Massachusetts, Lime, Bird and Spin, told NBC10 Boston that safety is their top priority, and that they continue to improve their technology to help riders.
Still, Hamilton — the selectwoman who pushed for Brookline's pilot — said she's staying off e-scooters for now.
"I'm just a little more risk averse ... because I'm older and I know what can go wrong," Hamilton said. "We are not doing our part to make sure everyone is safe in the space."
She said the Brookline pilot has shown the need for more regulation and oversight, more money for enforcement and protected lanes for bikes and scooters to keep them off sidewalks.
"You're watching out for car doors," she said. "You're inches from motor vehicles that don't obey the speed limit. And then, when a double-parked car is in your way, what do you do?"
Brookline has made some changes, including creating parking corrals and designating areas where scooters are slowed down or prohibited. Hamilton's advice for Boston is to negotiate with scooter companies to help pay for safety improvements.
For Kim Smith, the answer is easy.
"I'm keeping my distance," she said.
Abigail Hadfield contributed to this report.