Research
The LEVER Institute began with a multi-stakeholder workshop that identified five key research themes that address many of the main micromobility questions faced by stakeholders and are consistent with the expertise of the LEVER research team. We focus on how micromobility vehicle impact transportation systems.
The LEVER Institute focuses on aspects of micromobility vehicles that address the interests of both public- and private-sector industry partners. Much of the initial focus was (and still is) on e-bikes and other derivatives (e.g., e-trikes). However, the scope of the institute is broad enough to investigate other unforeseen LEV technologies (e.g., e-scooters). Many of the important questions about LEVs hinge on behavioral aspects of how LEVs are ultimately adopted and used.
The LEVER Institute focuses on the following thrust areas. Click on each or scroll down to learn more about our ongoing or past research:
THRUST 1: BEHAVIORAL ANALYSIS OF MICROMOBILITY VEHICLE USE
THRUST 2: MICROMOBILITY VEHICLE SAFETY AND SUSTAINABILITY IMPACTS
THRUST 3: HEALTH IMPACTS FROM MICROMOBILITY USE
THRUST 4: MICROMOBILITY AND URBAN FREIGHT
THRUST 5: SHARED MICROMOBILITY
THRUST 1: BEHAVIORAL ANALYSIS OF MICROMOBILITY VEHICLE USE
This theme will include research efforts to understand how users consume, use, and value LEV technology. This theme will focus primarily on consumer adoption and use of different LEV variants, with a primary emphasis on e-bike technologies. This theme will also include activities that explore the role of LEVs in shared vehicle and campus travel demand management activities.
National Electric Bike Owner Surveys (2013, 2018, and 2023)
Little research has been conducted on e-bikes within North America, especially on the individuals who have purchased e-bikes. The first-known U.S. nationwide e-bike owner survey was conducted by LEVER researcher Macarthur (PSU) in 2013. That study was updated by two other nationwide survey in 2018 and 2023 by LEVER researchers Macarthur (PSU) and Cherry (UTK). Analysis of the survey results indicate that there has been little change in the primary reasons individuals are motivated to purchase an e-bike, and they tend to be related to various barriers which deter individuals from riding a standard bicycle; reducing physical exertion, challenging topography and replacing car trips continue to reign as a few of the most important reasons for buying an e-bike. Importantly, the mode-substitution work from 2018 found that most e-bike trips substitute motorized modes, providing support to the position that e-bikes reduce car-based impacts. Both surveys were funded by People for Bikes and the Transportation Research and Education Center.
Publication:
A North American Survey of Electric Bicycle Owners
Link:
Project
The effect of e-bike incentive programs on adoption
LEVER researchers MacArthur, Bennett, and McQueen (PSU) and Cherry (UTK) research the effect of e-bike incentives on adoption. The first step in this effort was to assess e-bike incentive programs and how they are used to stimulate the market. That early work, funded by People for Bikes, was pivotal in developing an early white paper (link below) that identifies how incentives can nudge purchase behavior. This work also includes a policy simulator tool that allows users to identify how effective different incentives may be at reducing greenhouse gas emissions. This work is followed by ongoing research funded by the Transportation Research and Education Center (TREC) and People for Bikes that aims to understand individual-level purchase preferences using experimental stated preference methods to understand the levels of incentives and attributes of e-bikes that would cause the highest level of adoption. Our work has been heavily cited and referenced in ongoing incentive policies at the state and federal levels.
Publications:
White Paper
Project Brief
Consumer purchase response to e-bike incentives: Results from a nationwide stated preference study
Novel Approaches to Model Travel Behavior and Sustainability Impacts of E-Bike Use
LEVER researchers Cherry and Azad (UTK) and MacArthur (PSU) have partnered with and Bosch E-Bike Systems to measure real-world travel behavior and assess the sustainability impacts of those choices. This National Science Foundation (NSF) funded project develops novel smartphones-based machine learning efforts to assess trip patterns of a panel of e-bike users over two years. This supervised machine learning approach provides a wealth of data on actual e-bike use and avoids some of the pitfalls associated with surveys. However, this dataset compared with ad-hoc travel surveys to supplement passive data collection and, using machine learning algorithms, create the largest and richest dataset to support the growth of e-bike use as a transportation option. The data helps estimate implications on environmental sustainability using behaviorally sensitive environmental models. This four-year project is ongoing and has already amassed a wealth of data and informed policy.
Publication:
The E-Bike Potential: Estimating regional e-bike impacts on greenhouse gas emissions
Link:
Project
Understanding the difference between e-bike and conventional bike users
Publication:
Differences of Cycling Experiences and Perceptions between E-Bike and Bicycle Users in the United States
Evaluation of Electric Bike Use at Three Employment Centers
Employment based e-bike programs are growing in the USA. LEVER researchers MacArthur and Dill (PSU) were the first to evaluate such a program. This study examines the results of a pilot project, which took place April 2014-September 2015 in the Portland region. Participants from three Kaiser Permanente Northwest campuses (1 urban and 2 suburban) were issued an e-bike for 10 weeks to use for various trip purposes, focusing on first/last-mile commuting. Participants were asked to complete three surveys—before, during and after using the ebike—to evaluate how their perceptions and levels of cycling may have changed. Responses were analyzed using statistical software and a GIS. This study’s findings support the general hypothesis that e-bikes enable users to bike to more distant locations, bike more frequently and allow a broader participation in cycling for certain segments of the population by reducing barriers to cycling. This study was funded by the National Institute of Transport and Communities (NITC).
Publication:
Evaluation of an Electric Bike Pilot Project at Three Employment Campuses in Portland, Oregon
COVID-19 Impacts on Transit, Bike Share, and Scooter Share Systems
The COVID-19 pandemic has placed a burden on health care, the economy, transportation, and education around the world. LEVER researchers Cherry and Brakewood (UTK) and MacArthur (PSU) have partnered with Portland’s TriMet, Nashville’s WeGo, BIKETOWN, Bird, Spin, Lime, and the Transit app to investigate the interactions between micromobility use, public transit use, and public perceptions of risk, decision making, and mode choice factors. Funded by NSF rapid grant, comprehensive surveys were designed and sent out in 13 waves, including three intake waves from May 2020 until the end of September 2021. The study aims to examine the relationship between public transit ridership and micromobility use with respondents’ risk perception, attitudes, and sociodemographic characteristics and capture the changes through the pandemic. The findings of the analysis are expected to help policymakers and planners develop a comprehensive multimodal transportation network to cope with the external shocks that can strengthen the resiliency of the city during and after the pandemic.
Link:
COVID-19 Impacts on Transit, Bike Share, and Scooter Share System
The China E-bike Project
Electric bike use has reshaped the transportation system in a large number of cities in China. The massive adaptation of e-bike along with regular bicycles presents challenges common to another mode of transportation. This paper investigates e-bike use over six years with four bi-annual travel diary surveys of e-bike users between 2006 and 2012 in Kunming, China. Choice models were developed to investigate factors influencing mode-transition and motorization pathways. This effort is meant to identify how to use characteristics or demographics of users change over time and found that unobserved changes occur over time. This paper model these changes over time and introduces a mode-transition model, providing insights into how e-bikes could disrupt the traditional motorization pathway.
Publications:
Use characteristics and mode choice behavior of electric bike users in China
Dynamics of Electric Bike Ownership and Use in Kunming China, Transportation Policy.
Link:
Project
THRUST 2: MICROMOBILITY VEHICLE SAFETY AND SUSTAINABILITY IMPACTS
This theme will investigate research questions traditionally in the public domain. The primary focus will be the investigation of safety, sustainability, and mobility impacts of LEVs. Safety and sustainability of LEVs in the transportation system can inform policy related to the extent they should be encouraged or discouraged in the transportation system, and on what facilities they should operate.
The Safer Scooting Study
This project is a collaboration between faculty at Queensland University of Technology (Dr. Haworth), the University of Tennessee (Dr. Cherry), and industry partner Bird Scooter Company, funded by the Australian Research Council (ARC). Running from 2022 to 2025, the project aims to understand how and why people use e-scooters and how rider behavior and safety outcomes evolve with experience. The goal is to leverage the benefits of e-scooters as efficient alternatives to short car trips and to enhance access to public transport while minimizing risks to riders and pedestrians. The findings are expected to guide governments at all levels, industry, and riders in optimizing e-scooter design, usage, and regulation, contributing to improved transportation, health, and environmental outcomes for all Australians.
Link:
Project
BTSCRP-10: E-Scooter Safety: Issues and Solutions
LEVER affiliates Laura Sandt and Katie Harmon (UNC) and Chris Cherry (UTK) and outside consultants Dr. Sanders, Dr. Brown and Populus (Clewlow and Seki) joined this 30-month project to assess rider behavior issues associated with scooter use. E-scooters offer many potential benefits, including reduced air pollution in comparison to competing forms of transportation, first and last-mile connections to public transit, increased mobility options, and new revenue sources for cities. Recently, however, there has been a growing concern with injuries associated with e-scooter use. The objective of this research is to identify emerging behavioral safety issues arising from the expanding use of e-scooters, both rental and privately owned, and develop comprehensive guidance to help affected agencies plan for and mitigate related safety problems. The guidance should include tools, policy alternatives, educational materials, institutional requirements, and other relevant techniques to mitigate if not eliminate identified risks.
Publication:
E-Scooter Safety Toolbox (2023)
A crash typology to compare scooter and bicycle crashes
We conducted a comprehensive study to understand what demographics are involved in motor vehicles-involved e-scooter and bicycle crashes, under what circumstances such crashes occur, and what are the mechanisms of such collisions. In the first of its kind study, we compared and contrasted motor vehicle-involved e-scooter and bicycle police crash reports in Nashville, Tennessee, using the recent version of the Pedestrian and Bicycle Crash Analysis Tool (PBCAT). We found that e-scooter and bicycle crashes do not fully overlap with each other. The findings of the study imply that generalized engineering, education, and enforcement treatments to reduce or prevent e-scooter and bicycle crashes, injuries, and deaths might not yield a similar outcome for each mode. This research-to-practice study could help avoid e-scooter and motor vehicle crashes that contribute to 80% fatality of e-scooter riders.
Publication:
Research Paper: Comparison of motor vehicle-involved e-scooter and bicycle crashes using standardized crash typology, Journal of Safety Research
Presented at:
• International Cycling Safety Conference 2021, Lund, Sweden (online)
• Tennessee Department of Transportation (TDOT) Innovation to Implementation Forum 2021
Links:
• 80% of fatal e-scooter crashes involve cars – new study reveals where and why most collisions occur, The Conversation
• New Study Addresses E-Scooter Safety, UTK News
Sustainable Urban Mobility in Asia-Environmental Impacts of Electric Bikes-Clean Air
This study quantifies some of the impacts of the environmental impacts of the production processes and use phase of electric two-wheelers and compares them to the environmental impacts of the production processes and use phase of electric two-wheelers and compares them to the environmental impacts of competing modes, including bicycle, buses, motorcycles and cars. The biggest environmental reservation associated with electric bike is lead (Pb) pollution. This study discusses emission from the production processes, lead losses, and use phases of the electric bike and its alternative. The study found that the electric two-wheelers emit several times lower pollution per kilometer than motorcycle and cars, have comparable emission rates to buses and higher emission rates than bicycle.
Publication:
Comparative environmental impacts of electric bikes in China, Transportation Research Pard D.
Comparing safety related behavior between bicycles and electric bikes
The work was funded in part by the University of Tennessee, Knoxville, the Tennessee Department of Transportation, and the Southeastern Transportation Center. As suggested by the title this study develop a novel approach to safety behaviors analysis using naturalistic GPS data to evaluate the safety between regular bicycle and e-bike riders in context of a unique bike-sharing system. The study explored driving direction, speed and stopping behaviors of the users and found similar behavioral trend between both bicycle and e-bike riders. Similarly, the study also found that the users of both the technology had high violation rates of traffic control devices and suggests for some interventions to improve compliance.
Publications:
Risky riding: naturalistic methods comparing safety behaviors from conventional bicycle riders and electric bike users.
Comparing physical activity of pedal-assist electric bikes with walking and conventional bicycles
Link:
Project
THRUST 3: HEALTH IMPACTS FROM E-BIKE USE
Compared Physical Activity of E-scooters, Walking, and Driving
Following on their e-bike physical activity work, LEVER researchers Cherry, Wen, and Bassett are setting out to identify the level of physical activity of e-scooter users. They followed a similar approach to their earlier e-bike study. Here, they directly measure ventilation rates (using a Cosmed Fitmate) while riding a scooter, walking and driving the same course as the previous study. In addition, they conducted a fixed-maneuver trial of muscle activity on each mode using an EMG device, assessing activity of 15 muscle groups. As expected, scooter riding metabolic activity seems to fall between walking and driving. Upper limb and trunk muscle groups are higher for scooter riding than other modes.
Publication:
https://onlinepubs.trb.org/onlinepubs/conferences/2019/CHAT/Agenda.pdf
Comparing Physical Activity of E-bikes, Bicycling, and Walking
In one of the first measured e-bike physical activity studies, LEVER researchers Cherry, Bassett, Fitzhugh, and Langford (UTK) assessed and compared the metabolic activity generated by riding a pedal assist e-bike, a conventional bicycle, and walking along a fixed course with downhill, flat, and uphill sections. They estimated energy expenditure based on heart rate and ventilation rates (VO2). They found that e-bikes provide moderate physical activity (MET>3) on flat segments and downhill segments, and vigorous physical activity (MET>6) on uphill segments. Differences between e-bikes and bicycles are most pronounced on the uphill segment. For e-bike trials, riders reported higher levels of enjoyment and lower need for a shower than walk or conventional bicycle trials. E-bikes can contribute as an active transportation mode to meet required physical activity guidelines. This work was funded by the Southeastern Transportation Center and the Institute for a Secure and Sustainable Environment.
Publication:
Comparing Physical Activity of Pedal-Assist Electric Bikes with Walking and Conventional Bicycles.
Health Impacts of Emission from Electric and Traditional Motorized Transportation Modes in China
The study compared the emissions and environmental health impacts from the use of conventional vehicles and electric vehicles in 34 major cities in China. The study focusses on electric cars, electric two-wheelers including electric bicycles and light electric scooters in China. The study follows a conventional risk assessment framework and is based on pollutant intake. The study estimated exposure from emissions generated at more than 100 fossil EGUs. The study employed point estimates for input parameters and conducted Monte Carlo simulation to identify the sensitivity. The study also illustrated an example of the policy significance of the research by considering a deployment scenario for Shanghai. The findings highlight the importance of considering exposures, and especially the proximity of emission to people, when evaluating environmental health impacts for EVs.
Publications:
Electric Vehicle in China: emission and health impacts.
Environmental Justice Aspects of Exposure to PM2.5 Emissions from Electric Vehicle Use in China
Link:
Project
THRUST 4: URBAN FREIGHT LOGISTICS
Alternative Vehicles for Last Mile Freight
Publication:
Alternative Vehicles for Last Mile Freight
THRUST 5: SHARED LEVS
Big data analytics to assess travel behavior of shared micromobility use
Links:
Best Paper Award at: Tennessee Section of Institute for Transportation Engineers (TSITE)
Second Place at: Southern District Institute of Transportation Engineers (SDITE) paper competition
Publication::
Why do people take e-scooter trips? Insights on temporal and spatial usage patterns of detailed trip data.
Estimating demand elasticities of shared e-scooters.
We estimated the demand elasticity of deployed e-scooter vehicles by comparing actual demand (e-scooter usage) with supply dimensions (vehicles deployed). The study used almost a year-long geographically disaggregated e-scooter trip summary data and location of available e-scooters that updates approximately every five minutes from Nashville, Tennessee. We found that the demand for e-scooter vehicle deployment is inelastic, suggesting e-scooter trips increase at a lower rate than the increase in e-scooter vehicles deployed. The service providers with large fleet sizes (>500) have a demand elasticity of e-scooter deployment that is 1.4 times higher than that of medium fleet-sized service providers (250-500) and 3.5 times higher than that of small fleet-sized service providers (<250). These findings could be helpful for city governments to me identify the optimal number of service providers and fleet sizes to permit so that demand is fulfilled without an oversupply of e-scooter vehicles in public spaces.
Publication:
Presented at:
• Transportation Research Board 101st Annual Meeting 2021, Washington, D.C.
Bikeshare and E-bikeshare travel preferences in China
Links:
Project
Electric Bike Sharing-Evaluation of System Impacts
This published work presents the first-year operational experience of CycleUshare, an e-bike sharing system in the campus of the University of Tennessee Knoxville that combined the bike-sharing with e-bike. The CycleUshare is the North America’s first e-bike-sharing system that offered a sustainable transportation option for students, faculty, and staff. The CycleUshare system had two stations and was launched as a small pilot project to study the technology and its users’ experiences. The data for the analysis was based on the transaction log, GPS data, and survey questioner. The published work provides insights into the system’s users and trip characteristics during the first year of operations. Moreover, the program has provided an educational platform to introduce alternative modes of transportation and alternative vehicle technologies to thousands of students and staff.
Link:
Project
