Objective: safer bike lanes

In a recent investigation, the slip resistance of different pavements used in bicycle lanes has been analyzed.

The study has been carried out by the team of David Llopis Castelló, from the Polytechnic University of Valencia (UPV) in Spain, and has focused on existing bicycle lanes in Valencia, although part of the results can be extrapolated to other cities.

In 2018, the number of accidents in urban areas involving personal mobility vehicles did not reach 200 (there were 199, specifically), and in 2021 this number rose to 2,541. In the case of bicycles, the number of accidents was relatively stable in this period of time, going from 5,384 to 5,712. Of all of them, in 2021, the last year for which official data is available, 27% of these accidents occurred while riding an electric scooter or bicycle without interaction with Other users.

“In most cases, these accidents occur because the pavement was slippery. Therefore, the study of the slip resistance of the pavement is crucial to improve the safety of bike lanes. This resistance is one of the characteristics that most affects safety, since it has a decisive influence when it comes to accelerating, braking and maintaining the trajectory when turning the bicycle or scooter safely, without the risk of slipping or skidding.” explains David Llopis Castelló, a UPV researcher.

Thus, of the different pavements analysed, the researchers have verified that bituminous, concrete and rough tile floors provide adequate slip resistance and, among them, the first two offer the best performance, since they generate less vibrations and, therefore, a more comfortable displacement. “On the contrary, those with painted paving stones and smooth painted tiles do not meet the necessary requirements, and the probability of falls, collisions and conflicts between bicycle or scooter users, pedestrians and motorized traffic is greater” says Ana María Pérez Zuriaga, also from the UPV.

The authors of the study have analyzed the slip resistance of different pavements used in bike lanes in Valencia. (Photo: UPV)

The authors of the study also measured the speed of users of bicycles and electric scooters to analyze their behavior and the influence of pavements on braking distance. As a conclusion, the pavements that provide greater adherence (bituminous, concrete and rough painted tile pavement) allow a reduction of the required braking distance of up to 7.5%, while the smooth painted tile pavement increases the distance. braking required by 7% when driving at 20 km/h (speed limit on bike lanes), with the consequent risk.

Based on everything analyzed, the authors of the study propose that, on roads shared by motorized vehicles and users of bicycles or electric scooters, as well as on bike lanes on roads delimited with road markings, the paving material used is asphalt. . Also for protected bike lanes, although concrete paving can also be used on these. Meanwhile, for bike lanes located on sidewalks, the best option is rough tiles, since the vibrations experienced by users could prompt them to slow down.

In addition, the study proposes the minimum stopping visibility distances required to guarantee the safety not only of bicycle and scooter users but also of pedestrians and motorized vehicles.

“The results of this study can serve as a basis for improving the security of the micromobility infrastructure. When choosing pavements for newly built bike lanes, it is essential to take into account a parameter such as slip resistance, always accompanied by preventive control during the pavement’s useful life,” concludes Alfredo García García, coordinator of the Research Group on Highway Engineering from the UPV.

The study is titled “Skid Resistance Analysis of Urban Bike Lane Pavements for Safe Micromobility”. And it has been published in the academic journal Sustainability. (Source: UPV)