E-Bikes Can Improve Urban Travel Mobility, Efficiency, NREL Study Shows

E-Bikes Can Improve Urban Travel Mobility, Efficiency, NREL Study Shows

Research into the impacts of e-bikes on efficient, equitable, and sustainable mobility revealed the platform’s promise in some urban settings.
Do automobile drivers dream of electric bikes? They might, as a new study seemed to find a preference for e-bikes in Denver when commuting and taking short trips, even if roads weren’t cycling-friendly. 

The National Renewable Energy Laboratory (NREL) used its travel data collection technology, OpenPATH, to measure the efficiency of city transportation. The team calculated how efficiently individuals could reach employers, goods, and services when using e-bikes, regular bicycles, and auto vehicles. The resultant robust figures are the Mobility Energy Productivity, or MEP, metrics for these modes. 

NREL selected the Mile High City out of six locations that were part of a two-year pilot by the Colorado Energy Office that started in spring 2021, providing 181 e-bikes and 50 electric bicycle-share memberships to low-income essential workers in different locations around the state. 

Why study the use of e-bikes? “Electric bicycles were the best-selling electric vehicle in the United States,” said K. Shankari, principal investigator with the Center for Integrated Mobility Sciences at NREL. And about three-fourths of trips in the U.S. are shorter than 10 miles, “a distance that is well within e-bike range,” explained Shankari, who developed OpenPATH, full name Open Platform for Agile Trip Heuristics. Then there’s the much lower sticker price compared to cars. 

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The Denver results are highlighted in "Mobility Energy Productivity and Equity: E-Bike Impacts for Low-Income Essential Workers in Denver,” co-authored by Shankari and published in Transportation Research Record: Journal of the Transportation Research Board

"Tapping into OpenPATH data from nearly 50,000 trips, MEP calculations showed that several locations in downtown Denver provided time-, cost-, and energy-efficient access to opportunities using e-bikes compared to driving," said Christopher Hoehne, NREL mobility systems research scientist, in a statement. 

The ratio of e-bike MEP to drive MEP across metro Denver. A value of 50 percent corresponds to a location with an e-bike MEP score half the magnitude of a drive MEP score. Image: National Renewable Energy Laboratory
The OpenPATH platform consists of a smartphone app, server, and analysis pipeline to automatically create travel diaries and allow participants to add trip-level labels.  

“So, all trips taken by the user were recorded, and they were allowed to label them as ‘e-bike,’ ‘drove_alone,’ ‘shared_ride,’ etc.,” Shankari said. 

When comparing the MEP ratio of e-bikes to driving, researchers found 12 areas in Denver where the e-bike MEP was comparable in magnitude to the drive MEP, providing 80 percent or more of the energy-efficient access that driving provides. 

“Participants used e-bikes to commute more than cars, but driving was still the most prevalent mode,” added Venu Garikapati, team leader for transportation modeling and metrics at the Center for Integrated Mobility Sciences. 

Garikapati noted the overall e-bike MEP for Denver was 34, slightly greater than a quarter of the drive MEP of 129 but more than twice as high as the regular bike MEP of 16. 

“This shows that after taking time, energy, and cost factors into account, e-bikes are an alternative that can provide a level of access closer to driving compared to non-motorized modes,” he said. 

One big surprise came along when the team observed a disconnect between the frequency of e-bike trips and locations with higher MEP scores. “The locations where e-bike trips were made in higher numbers had lesser access to opportunities—that is, lower MEP scores—using that mode,” Garikapati said. “This can be a consequence of reduced density as well as lack of roadway infrastructure to support e-bike travel.” 

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The upshot is that this shows e-bikes were an attractive modal alternative, given that participants used them even when the infrastructure was not fully supporting the mode, he said. 

There’s much more work to do with data from the pilot program and the NREL study. Shankari noted that the team has yet to determine the number of users who made the 50,000 trips. And other figures could be useful for future analyses and city transit planning. 

“MEP is able to take travel behavior information that was collected from the participants in Denver and translate it to e-bike ‘quality of mobility’ per neighborhood,” she said. “Note that while downtown Denver has very good scores, the outlying suburbs do not. This indicates ‘focus areas’ where the infrastructure needs to be improved to increase bicycle ridership.” 

Though Denver is a Mecca for bicyclists—manual or electric—other localities can partner with the NREL for their own programs, and a “version of OpenPATH is available for free to public agencies, universities, and nonprofits in the U.S.,” Shankari said. 

Whatever else the team finds, NREL will make the data available, but won’t issue full-on recommendations. 

"We provide the scientific results to inform policymakers in their deliberations. So, we can say the current evidence indicates that if e-bikes are provided to low-income essential workers, they will use them, and the bike will, in some areas, be comparable to a car in the mobility that it enables,” Shankari said. "The policies under which e-bikes should be provided, whether only low-income workers should be targeted, what the amount of [a] rebate should be–all of these enter the realm of politics and we cannot provide opinions on them.” 

Eydie Cubarrubia is an independent writer in New York City. 

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