People in Denver ride rentable scooters an average of more than 17,000 times a day, sometimes as many as 30,000 times a day, according to the city’s Micromobility Dashboard.
And while the city says the electric scooters have replaced about 4.2 million automobile trips on Denver’s busiest streets, a grimmer statistic tempers that progress: Since the scooters first appeared in May 2018, more than 2,500 riders have arrived at Denver Health Emergency Department with scooter-related injuries, including broken bones and fractured skulls. And there have been five deaths.
At Craig Hospital, the local center for brain and spinal cord injuries, patients with traumatic brain injuries sustained in scooter accidents are now a “common occurrence,” according to Eric Spier, medical director for the hospital’s Brain Injury Program.
Between January 2021 and October 2022, Denver Health emergency physicians reported seeing an average of 3.6 scooter-related injuries per day. Other area hospitals have also reported seeing an increasing number of scooter injuries.
“People do not understand how dangerous they can be,” said Dr. Mia McNulty, an orthopedic surgeon and co-author of a new study on scooter injuries published in the Journal of the American Academy of Orthopaedic Surgeons. “They can be a new efficient way of transportation, but people should recognize that they shouldn’t use them while intoxicated and that they can be dangerous if used incorrectly.”
The company Lime first deployed a few hundred scooters on Denver streets in May 2018 with little warning and no approval from Denver authorities. The city soon launched a pilot micromobility program for e-scooters and e-bikes with Lime and four other vendors. In May 2021, the city signed five-year contracts with Lime and Lyft to deploy rental e-scooters and e-bikes around town. In recent months, there have been an average of about 3,500 scooters on Denver streets.
E-scooters are increasingly available in cities and towns attempting to replace short trips in a vehicle with travel on two wheels. The networks allow people to pick up a scooter on the street, activate it using a payment app, and then leave it at their destination. In the nearly five years since e-scooters showed up in Colorado, rental networks have deployed in Boulder, Fort Collins, Colorado Springs and Pueblo.
McNulty was an orthopedic surgery resident when scooters first arrived in Denver and she often consulted to the Denver Health Emergency Department on evenings and weekends. She and orthopedic surgeon Dr. Alexander Lauder quickly began to see people with scooter-related injuries.
“We started seeing a lot of patients come in with very bad injuries from these scooters,” Lauder said. “Since then, it has been just week after week of bad scooter injuries.”
Lauder described one young woman who shattered both her forearms and took more than a year to recover. Another patient ended up in the intensive care unit after dislocating and fracturing both elbows.
McNulty and Lauder decided to look more closely at scooter crashes and injuries. They and their colleagues reviewed medical records from the Denver Health between August 2018 and February 2020. They identified 197 patients who had were treated for scooter-related injuries at the Emergency Department.
Of the 197 patients with scooter related injuries that McNulty and Lauder investigated, about two-thirds suffered broken bones. Fractured forearms and lower legs were most common.
“The most common injuries are the injuries they get when they fall and try to protect themselves,” McNulty said.
Half of the broken bones required surgery. A third of all patients with scooter injuries were admitted to the hospital. Hospital costs averaged $14,200.
The researchers focused on orthopedic injuries. But they also documented 38 facial fractures and 31 head injuries or skull fractures, which are not considered orthopedic injuries.
“It is not uncommon to see people that have head injuries alongside their orthopedic injuries,” McNulty said. “The head injuries are a really important part of it.”
The researchers also did not include collisions with automobiles or pedestrians in their study. Their experience, however, convinced them that those collisions are a significant part of the mix. Scooters frightening and crashing into pedestrians are major concerns in downtown neighborhoods.
“People are extremely frustrated … by scooters careening down sidewalks,” said Denver City Councilor Chris Hinds, whose district includes portions of downtown.
It’s not just the rental scooters
Shannon Love hit her head in a scooter crash and suffered a concussion. She considers herself immensely lucky.
An avid bicyclist, Love, 46, bought an e-scooter to ride the 3½ miles between her home in Washington Park and her job in Capitol Hill. She wanted to reduce the environmental impact of commuting alone in her car. On the e-scooter she could ride dressed for work, arriving fresh, not sweaty from a bicycle ride.
“I loved it,” Love said.
About a month into her e-scooter commute, she was coming into the intersection at Grant Street and East 10th Avenue at a pretty good clip, maybe 15 miles per hour, when she realized she would not make it through the intersection before the light turned red and cars might hit her.
“I slammed on my brakes really hard and went head-first over my scooter into the pavement,” Love said. Unlike most e-scooter riders, she was wearing a helmet. That made all the difference. When her head slammed into the concrete, the helmet took the direct impact.
“I can’t imagine what the impact on my skull would have been without my helmet,” Love said. “I believe I would have had a traumatic brain injury.”
Indeed, e-scooter accidents have resulted in numerous traumatic brain injuries that land patients at Craig Hospital.
“We have progressively seen more of that type of injury over the last several years to the point that it has gone from being an unusual incident to a common occurrence,” said Dr. Eric Spier, medical director for the brain injury program at Craig Hospital. “There is almost always a patient with a severe head injury in the hospital that we are caring for whose life has been unalterably changed by a scooter accident in our community.”
Spier suspects that his neurosurgical colleagues around the region have seen many more patients than he has because, “I see only the worst of the worst.”
Spier said brain injury patients he sees can have difficulty not only with their cognitive function, but also face problems from seizures to abnormal bone formation, difficulty swallowing and breathing, paralysis and an inability to speak.
Love suffered a concussion, a broken arm and facial cuts that required a dozen stitches. The concussion left her a “hot mess” for several days and she could not support any weight with her injured arm for three months. She has scars on her face, which is still numb in spots.
Love sold her scooter and says she will never ride again. Neither will Dr. Eric Lavonas, emergency physician at Denver Health.
“I used to ride them, but after seeing what I see at work, I don’t get on them at all,” said Lavonas. “Too many bad things are happening to too many people.”
Number of serious injuries have risen as scooting gained traction
During the 16 months of McNulty and Lauder’s study, early in the scooter era, only 197 patients came to the Denver Health Emergency Department with scooter-related injuries, about one every three days. Since then, scooter rides have increased two to threefold. And scooter-related injuries kept pace.
Recently, Denver Health reported that 2,381 patients came to its emergency room with e-scooter injuries between Jan. 1, 2021, and Oct. 19, 2022, an average of 3.6 per day. While those numbers could include a few disabled people riding mobility scooters, the vast majority are e-scooter riders, according to April Valdez Villa, a spokeswoman for Denver Health. That 26-month reporting period may camouflage higher numbers in recent months.
“That number has definitely escalated, especially this summer,” said Dr. Daniel Cheek, an emergency physician at Good Samaritan and Lutheran hospitals. He researched e-scooters and delivered a talk to his colleagues in 2021. “They are dangerous.”
According to the Denver Medical Examiner, five people have died in scooter-related accidents since 2019. Three of those deaths involved motor vehicle accidents and two were scooter-only crashes.
The rising tide of scooter crashes and injuries results from a volatile combination of physics and human behavior. “The risk of accident depends both on the scooter itself as well as on the rider,” said Mehdi Ahmadian, director of the Center for Vehicle Systems and Safety at Virginia Tech.
Ahmadian highlights the features of scooters that make them prone to crashes. The standing posture of riders puts them in a precarious position. It is made even less stable by the narrow stance riders can take on “limited real estate” on the scooters’ footboards. Think of building blocks. The tall, skinny block tips over at the slightest push, while the squat square or triangular block withstands much greater forces. A bicycle rider with a lower center of gravity and weight distributed widely between the handlebars and seat is more stable than a scooter rider.
Ahmadian also points to the small wheels on the rentable scooters, which are less suitable for the rough terrain than larger, inflatable tires seen on bicycles and some scooters.
“That small wheel does not roll over the bumps in the road,” Cheek said. “The only thing going forward is you.”
A spokesman for Lime, one of the companies serving Denver with undocked scooters, noted that newer scooters have larger wheels, wider decks and handlebars that put the rider in a more upright position.
He also said the company has recorded more than 6 million rides on Lime scooters in Denver since launch, with fewer than 600 accidents reported by riders. Of those, he said, 28% required medical attention.
Rentable scooters in Denver are limited to 15 miles per hour. But that speed is faster than most humans can run, Denver Health’s Lavonas noted.
“If you imagine yourself running as fast as you can into a brick wall, you would expect to get pretty seriously hurt,” Lavonas said. “That’s the same physics as a scooter crash.”
Alcohol was a contributing factor to at least 20% of injury crashes
But as Ahmadian pointed out, the risk of crash and injury depends on the scooter and the rider.
Medical professionals interviewed for this article all pointed the finger at riders who do not appreciate the risks the scooters; fail to take precautions common among bicycle riders and car drivers; and often take a relatively cavalier attitude toward riding two-wheeled motorized vehicles on busy city streets.
“I think a lot of people go downtown and they have no experience on a scooter, no athletic talent per se, did not grow up riding skateboards or scooters, and they suddenly get on one with their girlfriend and no helmet after a few drinks in the dark. And that is just a recipe for disaster,” Craig Hospital’s Spier said.
Scootering while intoxicated is a major problem. In McNulty’s study 73% of injured scooter riders who were tested were intoxicated. That may be an overstatement since it included only riders whose behavior inspired emergency physicians to test them. The raw number of confirmed intoxicated riders among the 197 people injured in scooter crashes was about 20%. Another study in Austin, Texas, estimated that 29% of injured scooter riders were intoxicated.
Denver Health’s Lavonas thinks the number is much higher. Sober patients certainly crash and injure themselves, but “most patients with serious injuries were intoxicated at the time they were operating the scooter,” Lavonas said. “I’d say 80 or 90 percent.”
And they don’t wear helmets. Yet, as Love’s experience demonstrates, helmets can make all the difference. She suffered a concussion instead of a life-altering skull fracture.
“You wouldn’t let your kid on a bicycle without a helmet,” said Craig Hospital’s Spier. “If you are getting on a motorized vehicle without a helmet, even if it’s not at night and it’s not after a drink, it’s a bad idea.”
But that is a difficult ask when people are downtown. Hazel Creighton, 21, has seen the messages on her scooter rental app urging her to wear a helmet. “I am downtown with my friends at dinner. I don’t have a helmet with me,” Creighton said.
The lengthy scooter service agreements warning riders of risks and telling them not to ride dangerously are also rarely read. “But you are on your phone and you are just trying to ride,” Creighton said. “You press agree, agree, agree, not really reading anything.”
However, as Vanessa Lacayo, marketing and communications specialist with the city’s Department of Transportation and Infrastructure noted, most people ride safely and without incident.
And scooters offer a new form of transportation that can reduce traffic congestion, are less expensive and more efficient than automobiles, and could solve the “last mile” problem of public transportation. A survey conducted by DOTI during its scooter pilot program indicated that about 30% of scooter riders would have taken an Uber or Lyft or their own car if scooters had not been available. DOTI estimates that 13.7 million scooter trips in Denver replaced about 4.2 million car trips.
“During the pilot, we were effectively able to reduce single-occupancy vehicle trips, improve connections to shared public transit and provide better ways for people to get around,” Lacayo wrote in an email.
It is difficult to know if scooter crashes and injuries are unreasonably high, as few comprehensive studies have been done. The Safe Micromobility report produced by the International Transportation Forum in 2020 reviewed several studies of e-scooters in cities worldwide. It concluded that e-scooters pose no greater risk of fatality than bicycles and less than motorcycles or cars. However, the report did note that risk of hospitalization was greater among e-scooter riders than bicyclists.
There are a host of possible strategies to reduce scooter crashes and injuries, which the city and scooter operators are pursuing to varying degrees. These include safer scooters, technological curbs on riding speed and location, teaching riders how to ride more safely, more bike lanes, smoother roads and more enforcement of illegal riding. (For the record, it is illegal to ride intoxicated, with more than one person per scooter, or on sidewalks except slowly when starting or ending a ride.)
“I think the most important thing is that people understand the risk associated with riding these scooters,” said McNulty. “I think it is underrecognized, which is why we did the study.”
UPDATE: This story was updated Dec. 14 at 12:50 p.m. to include information about Lime’s new scooter style and data from the company about the number of accidents requiring medical attention reported by customers.