Crashes on electric scooters are mostly due to the behaviour of the riders, with one-handed steering and riding in a group being some of the largest risk factors. The researchers are also concerned about riders who deliberately crash or cause dangerous situations when riding, a phenomenon that seems to be specific to electric scooters. This is shown by a study from Chalmers University of Technology in Sweden, which for the first time examines the causes behind crashes with electric scooters from naturalistic data within an urban environment.

The arrival of electric scooters in cities has meant an opportunity to quickly and smoothly make shorter trips. But not everyone is using them to simply get from A to B.

"When working with road safety, it is important to understand that electric scooters not only meet mobility needs in cities but are also used for pleasure. Unfortunately, it is clear that leisure riding in some cases leads to dangerous behaviours that increase crash risks," says Marco Dozza, Professor of Active Safety and Road User Behaviour at Chalmers and one of the authors behind the recently published study.

The study is the first of its kind and is an investigation of risk factors and causes of crashes with electric scooters in urban environments. While the findings clearly show that the vast majority of e-scooter riders do not demonstrate risky behaviour, the study focused on the safety-critical events that occured.

Using advanced technology and cameras attached to the vehicles, data was collected from almost 7 000 trips with rented electric scooters. This data allowed the researchers to examine the causes of the 61 safety-critical events that were identified, including 19 crashes and 42 “near-crashes”– critical situations that could have led to a crash.

A phenomenon that was discovered surprised the researchers and clearly differs from studies of other vehicle types: in 20 per cent of safety-critical events, the rider deliberately created a risk situation or collision while driving. Because the incidents were intentional, they were not included in the analysis of crash risks, but Marco Dozza sees significant concerns with this behaviour, which he thinks can be likened to a type of vandalism. He points out that there are not the same established social norms for the use of electric scooters as for other types of vehicles.

"This behaviour seems to be specific to electric scooters. The lack of ownership because the electric scooters are rented may make the rider feel less responsible for the vehicle and care less about the consequences of a crash," he says.

Odd riding behaviour reduces focus
According to Marco Dozza, the study shows that it is primarily the rider's behaviour that causes crashes, not the electric scooter as such.

"There are significantly more varied, strange, and dangerous behaviours among electric scooter riders compared to other road users," he says.

And the dangerous behaviours have consequences. The study shows, for example, that riding with only one hand on the handlebar increases the risk of crashing by six times. Riding together in a group, or using a mobile phone during the journey, almost triples the risk of a crash occurring.

"It is not possible to steer and brake with an electric scooter in the same way as with a bicycle, so riding with one hand on the handlebar is significantly more difficult – and dangerous – than many people might think. The results confirm how important it is not to be distracted while driving. Looking at your mobile phone or riding with many people in a group can take the focus away from driving and the surrounding environment," he says.

An important take away from the study is the importance of experience when riding an electric scooter.

"The risk of being involved in a crash is greatest the first time you ride an electric scooter. For those who have ridden less than five times, the risk is still more than twice as high," he says.

Another conclusion is that the type of trip the electric scooter is used for matters a lot. Commuting to and from work, or to another designated point, leads to fewer crashes than more aimless riding or riding where the user takes detours on the way to the destination.

Unexpected number of incidents with cars
Of the critical events analysed, almost 20 percent involved other electric scooters, 16 per cent pedestrians and 5 percent bicycles. Most critical events, 30 percent, occurred with cars. As an unprotected road user, you risk serious injury from a car crash, points out Marco Dozza, who is somewhat surprised by the results.

"Since bicycles and electric scooters should be ridden on bike lanes, I had expected more conflicts with bicycles. The fact that so many cars are involved suggests that many crashes may occur when the electric scooter is ridden outside the bike lanes, or when there is no bike infrastructure available. The risk of crashes is greatest at intersections, and my impression, even though this is not something that the study has concluded, is that it may be difficult for motorists to see the electric scooter riders in time, especially if they are not riding on a bike path," he says.

According to the researchers, technical solutions can improve the traffic safety of electric scooters. For example, technology can warn of dangerous situations and remind the rider to keep both hands on the handlebars. Technology can also keep track of how the driver is using the vehicle and identify whether it is being ridden as part of a ‘pack’ or if the rider is using a phone at the same time. Geofencing can employ this information to automatically adapt vehicle speed to crash risk.

At the same time, Marco Dozza believes that it is behavioural changes, possibly nudged by technology, that can make the biggest difference to road safety in the short run. He is convinced that education and training are important ways to reduce the number of crashes.

"Parents can teach their children to ride an electric scooter in the same way as they teach them to ride a bike. Maybe there is a need for education, and preferably practical training, to be able to rent an electric scooter," he says.

The study has been funded by the Swedish Transport Administration.
" This is an important research project because it concerns a new, relatively unresearched area, where accidents increase in line with use. The results show that a combination of training and technical solutions on the electric scooter can be effective in reducing accidents and injuries," says Rikard Fredriksson, senior expert in vehicle safety at the Swedish Transport Administration and adjunct Professor, Division of Vehicle Safety, Chalmers University of Technology.

More about the research
The study, Understanding factors influencing e-scooterist crash risk: A naturalistic study of rental e-scooters in an urban area was published in Accident Analysis & Prevention.
The authors are Rahul Rajendra Pai and Marco Dozza at Chalmers University of Technology. The study was funded by the Swedish Transport Administration, within the FFI project e-SAFER, led by Chamers. The study was approved by Etikprövningsmyndigheten (2023-04671-01).

How the study was conducted
Data was acquired from 17 extra-equipped electric scooters for rent in Gothenburg and data was collected from 6,868 trips made by 4,694 electric scooter riders over a total distance of 9,930 kilometres. Data included speed, accelerations, and how the brakes were used. The vehicles were also equipped with cameras aimed forward to facilitate the analysis of risky situations.

Risk factors when riding an electric scooter
The figures indicate how many times the risk of crashes and safety-critical events increases with different behaviours and types of conflict vehicle.

Riding - Number of times increased risk of safety-critical events
One-handed control: 6.5
Riding in a group (pack riding): 2.7
Mobile use while riding: 2.7
Rider experience ≤ 5 trips: 2.2

Type of trip - Number of times increased risk of safety-critical events
Aimless riding/detours vs point to point: 4.9
Leisure riding vs commuting: 2.4

The proportion of vehicles involved in safety-critical incidents
Passenger car and van: 30,2 per cent
Electric scooter: 19 per cent
Pedestrian: 15.9 per cent
Bicycle : 4,8 per cent