Comparing the vibrational behaviour of e-kick scooters and e-bikes: Evidence from Italy

E-kick scooters are currently among the most popular emerging electric-powered Personal micro–Mobility Vehicles (e-PMVs) and have recently been equated to e-bikes. However, even if the dynamic behaviour of e-bikes is well studied, much less has been done to understand the behaviour of e-kick scooters. Furthermore, comparisons between the two vehicles have rarely been investigated and only based on mechanical models. This study covers this gap by proposing a novel framework that evaluates the vibrational behaviours of both vehicles when driven by different users and exposed to the pavement irregularities, using both real and simulated data. The experimental data are collected equipping an e-kick scooter and an e-bike with Inertial Measurement Units, and then processed by ISO 2631–1 method to obtain an objective evaluation of the comfort. Next, the experimental data are expanded to include uncertainty applying a Monte Carlo Simulation based on a two-layer feed-forward Artificial Neural Network. Afterwards, several statistical analyses are performed to understand the key factors affecting the vibrational magnitude (and their extent) for each vehicle. This framework was tested in an Italian city (Brescia) along urban paths with five different pavement surfaces. The results showed that the e-kick scooter appears to be globally more solicited than the e-bike in terms of vibrational magnitude. Moreover, pavement surface, sensor position, user gender, user height, and travel speed are identified as crucial factors explaining the vibrational magnitude for both vehicles. The overall findings challenge the recent European regulations that equated e-kick scooters with bikes. These findings may help public administrations in planning the circulation of e-bikes and e-kick scooters in cities and recommend that manufacturers improve the e-kick scooter design by including shock absorbers to increase comfort.