Electric scooters increase ride-sharing, reduce bike-sharing and raise safety concerns

A new study by marketing experts at the University of Illinois at Urbana-Champaign finds that electric scooters, one of the fastest-growing forms of urban transportation, are reshaping urban mobility in unexpected ways.

The introduction of shared electric scooters in Chicago increased demand for ride-sharing services, but decreased the use of shared bikes. It’s also associated with increases in street and vehicle-related crime in neighborhoods, says a new study co-authored by Unnati Narang, a business professor at the Gies School of Management.

The findings, published in the Journal of Marketing, a joint project between Ruichun Liu of San Jose State University and a former graduate student from Illinois State, question common assumptions about the benefits of electric scooters, Narang said.

“While electric scooters have been hailed as a green innovation to boost retail activity, their impact goes beyond what we know from the marketing literature,” she said. “Our study documents for the first time the impact of electric scooters beyond retail stores and restaurants, and shows how electric scooters are reshaping shared mobility systems and public safety in ways that policymakers need to take seriously, as they incur economic and environmental costs.”

Researchers analyzed the introduction of electric scooters in the city of Chicago during the summer of 2019. The city of Chicago authorized 10 companies to rent electric scooters across a 50-square-mile area on the city’s west and northwest sides.

Using data from more than 8 million rideshare trips, more than 750,000 bikeshare rides, and detailed crime reports across 866 census tracts, the researchers applied a statistical method known as “generalized synthetic control” to measure how e-scooter use changed travel and crime patterns compared to similar areas without e-scooters.

Their analysis covered 41 weeks of data and captured both pre- and post-implementation trends in mobility and safety.

The availability of electric scooters increased short rideshare trips by 15.7%, but bikeshare programs decreased trips in areas where scooters were available by 7.6%. This suggests that riders often use electric scooters instead of rented bicycles.

“The rise in ride-sharing trips on electric scooters reflects what we call a category expansion effect,” said Narang, a John M. Jones Marketing Fellow and Deloitte Scholar. “E-scooters are encouraging people to take trips they might not otherwise have taken, and they often combine travel with ride-sharing. For example, you can go to dinner on an e-scooter and then hail a ride-share vehicle to go home. Or you go to the grocery store but need to take your shopping bags home.

“However, we also found that electric scooters do not increase demand for bike share. Electric scooters directly compete with demand for bike share. This is a classic case of category cannibalization, despite the overall need for new travel increasing.”

Electric scooters expanded mobility and created new economic activity, but at the same time, the number of reported crimes increased by 17.9%, concentrated in road and vehicle-related crimes such as car break-ins and theft.

The researchers emphasized that this increase in crime represents a hidden social cost that cities should consider when evaluating urban transport policies.

“Electric scooters are portable and fast, making them an attractive tool for criminals of opportunity,” Narang said.

The researchers also noted that the impact of electric scooters was not evenly distributed across neighborhoods.

Neighborhoods with higher percentages of minority residents saw an increase in ride-sharing compared to neighborhoods with fewer minorities, but crime also increased in those same communities. In contrast, bike share substitution was strongest in minority neighborhoods.

Similar differences were found in age patterns. In younger neighborhoods, scooters were associated with a 20.6% increase in crime, much higher than in older neighborhoods.

“These patterns suggest that the benefits and costs of electric scooters are not evenly distributed, and electric scooters may inadvertently exacerbate inequalities,” Narang said. “Communities of color and young neighborhoods account for a disproportionate share of the crime increase.”

Despite their eco-friendly image, electric scooters are not a replacement and may not provide any environmental benefits, as they fuel an increase in short-distance rideshare trips.

“While electric scooters are often viewed by policymakers as an environmentally friendly alternative, the net environmental impact is negative because electric scooters increase short-distance ride-sharing trips rather than replacing electric scooters,” Narang said. “In fact, we found that while rental electric scooters contributed approximately $8.1 million to ridesharing revenues, they also had unintended negative environmental impacts amounting to more than 800 tons of carbon emissions per year.”

To offset this annual emissions, “about 36,000 trees would need to grow in one full year,” Narang said. “We can explain the trade-offs with other similar environmental initiatives and simple behind-the-scenes calculations.”

The findings highlight the need for more nuanced electric scooter regulation, the researchers said. The paper said cities may need to invest in protected lanes, introduce safety campaigns, develop strategies to limit opportunities for crime and work with local communities to ensure fair returns.

“Cities should not assume that electric scooters automatically promote sustainability or provide a level playing field in terms of mobility,” Narang said. “They create a lot of externalities, so regulations and planning need to address safety and equity head-on.”

To make the study results accessible, researchers developed a companion research app that allows policymakers and the public to interactively explore electric scooter data. This tool can model how future electric scooter deployments will impact different communities across the United States.

“We want our work to be practical,” Narang said. “This app allows stakeholders to predict how electric scooters will impact their cities and make more informed policy decisions. The app allows users to enter their zip code and make predictions based on the underlying impact, as well as chat with an AI agent.”