(CNN) — Brussels. San Diego. Bogotá. Walk around any major tourist destination these days, and you'll see them. Electric scooters, gliding silently around city center streets, zipping through traffic signals, or abandoned -- lying on the street, propped up against trees or, in some cases, dumped in rivers.
Scooter-sharing systems similar to city bike schemes have sprung up in more than 100 cities worldwide as their popularity has grown.
But this tiny-wheeled transport revolution could be about to end as quickly as it began.
While they've attracted admirers for their convenience and fun, they've also incurred the wrath of those annoyed at having to leap out of people riding across sidewalks or step over scooters lying in their path. There are also mounting safety concerns and questions about environmental claims made about using them.
This month, Singapore announced a trial prohibition of e-scooters on sidewalks that could become an all-out ban next year. It took the decision, says Lam Pin Min, senior minister of state for transport, following the death of a cyclist who collided with an e-scooter. Local news reports said one Singapore hospital had reported six deaths of scooter riders in 2019.
Meanwhile in France, a sidewalk scooter ban was enforced in September, three months after a rider was hit by a truck and killed.
In the UK, scooters are also banned from all public roads, sidewalks and cycle lanes -- although that hasn't stopped them being a regular presence on all three. The UK now insists that retailers including Amazon put safety warnings on packaging, a measure introduced in October, after a YouTube star, Emily Hartridge, was killed riding an e-scooter in London in July.
'Disproportionately affecting' those with disabilities
The scooter revolution has been billed as a green way to get around big cities, with rental apps acting in the same way as city bike schemes. You pick them up, pay by the minute and drop them off at your destination.
Where some city bikes often have docking stations -- to which the bikes must be returned for the fees to stop -- scooters can be picked up or dropped off anywhere.
And while that may be handy -- apps like Lime, Bird and countless local spinoffs have live maps showing users where the nearest scooters are -- it's causing issues for other road users.
"I predict these two wheeled electric scooters will become very annoying," he tweeted. "They seem to be abandoned, in the middle of the pavement, everywhere I go. I saw three from the station to my hotel."
Minty says that a friend who'd been to Paris said the situation in the French capital before the September ban was "exactly the same."
People with disabilities are "disproportionately affected," he says. "You're going to hit these, and you'll be absolutely stuffed."
Environmentally friendly -- if you're replacing a car
Scooters can be ditched by users wherever they like
Proponents of scooters say that they're environmentally friendly. "Cruise past traffic and cut back on CO2 emissions," trumpets Bird's website.
In fact, traveling by scooter has a higher carbon footprint than going by bus or moped -- as well as on a bike or on foot, according to Jeremiah Johnson, an associate professor at NCSU who led the research published in the Environmental Research Letters journal.
Instead of looking at scooter carbon footprint per journey, Johnson and his team looked at the entire lifecycle of scooters -- crucial because they are notoriously short-lived, he says, with customers mistreating them.
The materials used to make the scooters -- an aluminum frame, lithium battery and rubber wheels -- all result in an environmental burden, he says. As does the manufacturing.
"They have a really short lifetime, especially in this application of them," he tells CNN. "Aluminum doesn't provide much service. They only last several months."
What's more, because users can ditch them wherever they like, rental apps pay third parties to round up the scooters every night, grouping them more sensibly for the morning's customers, he says.
"They receive compensation per scooter, so there'll be folks doing this as a side hustle, students trying to make money -- it's a prime source of income," he says.
"It's very competitive and done in a very short window, and they're largely driving their personal cars to pick them up. That's a pretty big share of the impact."
Some e-scooters get thrown in rivers, canals or the sea.
GERARD JULIEN/AFP via Getty Images
Lime scooters are taken to warehouses each night by a local operations team, said a spokesperson. Senior director at Bird, Caroline Hazlehurst, said that Bird's scooters are collected "regularly, but not always every day... How we collect them changes from country to country."
But she added: "Every town and city throughout the world suffers from the same two problems: too many cars creating congestion which in turn leads to poor air quality."
Of course, they also need to be charged overnight. And the final thing to take into account is what method of transport they're replacing.
If you're scootering to work instead of driving yourself solo, the scooter is a "clear environmental win," says NCSU's Johnson. But, he says, many people surveyed in Raleigh, where the university is based, said that pre-scooter, they'd cycle or walk to work.
While many people in the US drive to work -- and Johnson is clear that "in moving away from car ownership it's almost certainly a win for environmental performance" -- in European cities, where public transport is the norm, using a scooter is therefore relatively less green, he says.
"Scooters look innocuous but people tend not to think about the unseen cost," Johnson says.
Hazlehurst says that Bird has changed its scooters from "consumer grade" to a "vastly different" and "rugged" version since they launched. Its "Bird One" model now has a lifetime of around 18 months, she said, while its latest model Bird Two can last two years.
Lime says that its third generation model is "demonstrating a lifespan of more than 12 months." Its spokesperson says that Johnson's study "raises important issues" but "doesn't capture Lime's approach today."
"We've already taken steps to reduce our environmental impact, including streamlining our charging operations, powering our scooters with 100% renewable energy, offsetting the emissions from fleet vehicles, and establishing a robust repair and reuse program to extend the life cycle of our products," the spokesperson said.
Where are scooters legal?
Singapore has announced a scooter sidewalk ban
ROSLAN RAHMAN/AFP via Getty Images
Rules on e-scooters vary around the world. In the UK, riding one on a road can net users six penalty points on their driving license. Riding them on the sidewalk, cyclepath or footpath is subject to a £300 ($385) fine.
A report by the UK House of Commons Library in August suggested that things could change in the future, but a spokesperson for the Department for Transport declined to comment, citing rules around the upcoming UK election.
In Paris, while you can ride them on the road, using them on the sidewalk can incur a €135 fine, while dumping them in a doorway, on a crosswalk or in another antisocial place incurs a €35 fine.
"Pavements are only for pedestrians," mayor Anne Hidalgo tweeted in March this year.
Germany approved e-scooter use this year, though not on sidewalks unless in "exceptional" circumstances. Bird's Caroline Hazlehurst says that "especially in Europe, we're seeing cities and countries change laws to specifically allow scooters to operate."
In Sweden, where scooters are classified as bicycles and allowed on sidewalks or footpaths, 241 accidents have been registered this year alone including one death. Tomas Eneroth, the Swedish minister for infrastructure, has called the situation "a mess." The law in Spain was changed this year. E-scooters can no longer be used on sidewalks. Additionally, they are banned in Barcelona. Madrid authorities in October refused to grant licenses to ride-sharing companies Bird, Lime and Voi.
Portland, Oregon, is midway through a year-long trial, following a four-month pilot in 2018.
The 2018 program "raised concerns about people riding e-scooters on sidewalks, in violation of state traffic laws, creating conflict with people walking and people with disabilities," says a statement from the Portland Bureau of Transportation.
The PBOT will "evaluate the program" following the pilot.
It used to be illegal to use the scooters in New York City, but a law change in summer 2019 means that you can use your own, if you have one -- although ride-sharing rentals are still banned.
And in LA, authorities this month suspended Uber's permit to rent e-scooters because of its failure to share ride-tracking data with the Los Angeles Department of Transportation. Seven other companies are licensed to rent scooters in LA though. And in San Francisco, the scooter companies were dubbed "spoiled brats" by Aaron Peskin, one of the legislators who voted to clamp down on the companies when they were introduced in 2018. In April 2019, however, the city granted permits to four companies: Jump, Lime, Spin, and Scoot, the last of which had previously been operating.
San Diego struggles to cope
Sidewalks are being crowded with the scooters, say critics
Mario Tama/Getty Images
San Diego has been at the forefront of scooter wars since the machines arrived in February 2018. The city is awash with more than 19,000 scooters, according to the San Diego Union-Tribune -- with almost 15,000 complaints about them to the city authorities over the summer, 3,700 scooters impounded for parking violations, and almost 500 riders receiving traffic tickets.
Since April, the city has instated "corrals" -- designated parking spots by the roadside for scooters, outlined with paint on the road. Riders can be fined for dumping a scooter on the street in a block that has a corral.
In April, the council introduced new restrictions on scooters, including speed limits in pedestrian-heavy places like Balboa Park, and a parking ban in places with speed limits below 8 mph, including beachfront boardwalks and in Little Italy.
Council member Barbara Bry, a vocal critic of the scooters, called for a moratorium in July, although it has not been approved. In December, the council will debate banning scooters on the beach boardwalks entirely.
"Throughout the city, I continue to see riders using the sidewalk, multiple riders on one scooter, and scooters strewn about the sidewalks, rather than in designated corrals," she tells CNN.
"San Diego was slow to respond when scooters started showing up on our streets. While it has been inactive, other cities like Portland and Santa Monica have issued requests for proposals that include a fee structure, operational standards, data sharing and insurance requirements."
She said the City has "let a technology overtake us rather than assist and empower our communities with safe and sustainable micro-mobility options," and said that "all of downtown is experiencing cluttered sidewalks."
"The corrals are overflowing with scooters that leak out into the road and automobile parking spaces," she said.
The mayor of San Diego was not available for comment.
Victims of scooter crashes are cashing in
Catherine Lerer, a personal injury attorney based in Santa Monica, where scooters were introduced to the United States, says that over the past 18 months, she's spoken to around 400 victims of scooter injuries -- both riders and pedestrians. She believes them to be more accident-prone than bikes because of their smaller, more solid wheels and a more precarious center of gravity for users.
"It's imperative that cities get ahead of any e-scooter rollout, otherwise they will be hamstrung in terms of regulating the scooters and sanctioning the operators," she tells CNN.
Authorities should ban nighttime use, sidewalk riding and allowing the scooters on roads that have a speed limit of more than 25 mph, she argues in a list of 25 recommendations.
She says authorities should also insist that riders wear helmets, prohibit sidewalk parking, install tech that alerts the companies if a scooter isn't upright, and fit the devices with lights, reflectors, turn signals, kickstands and identification numbers.
She says the devices should emit noises that can be heard by nearby pedestrians, to help those with disabilities.
For its part, Lime says it is tailoring its scooter roll outs so that they work with specific destinations and urges careful consideration before new legislation is introducted.
"Lime is committed to partnering with cities to build the right shared mobility program for each community," a spokesperson said.
"We know the positive impact micromobility can have on communities around the globe... and we're dedicated to collaborating with our city partners to tackle these challenges together.
"We support regulations that promote safety and greater transportation access without stifling innovation or consumer choice."
Scooter fans still keen
The weather in Miami makes it popular for year-round scootering
Despite the issues, though, the enthusiasm of scooter fans show no sign of waning -- and for some, replacing a putative car journey feels like the right thing to do.
Cyndi Hutchenson, a copywriter from South Florida, commutes via scooter most days -- a journey of around 10 minutes. She has a monthly pass, costing $15, which allows her 30 minutes of scootering per day.
"I don't have a car, and I don't really want one," she says. "I live downtown, and everything I want to reach is a relatively cheap Uber Pool away, if it's outside scooter limits. And I'm new to the city, so I want to get to know it better.
"I'm conscious of the environmental impact difference of riding an electric scooter versus riding in a car every day. I also know that, were I to have a car, I'd be making more unnecessary trips or traveling farther outside my neighborhood for things I can easily have a range of within a scooter ride
"The buses are not convenient (in terms of timing, cleanliness, safety, and payment methods) in my city and don't even go to my workplace."
The future of e-scooters
But as cities continue to clamp down, and the accidents mount up, scootering around the globe might not be free and easy forever.
"I don't want to be a killjoy, they do look a lot of fun," says Simon Minty. "They're exciting, new technology, they mean fewer cars on the roads -- but people have to realize that there's responsibility that comes with them.
"It's not just people with disabilities. Parents with prams, older people -- a whole bundle of people will be affected if we have to navigate round these scooters.
"I don't quite understand how people can just leave them in the street. It just blows my mind a little bit."