The problem of the appearance of the sliding effect in the wheel-road contact in railway transport is considered. It is known that the sliding effect accompanying the rolling process of the wheel is explained by two fundamentally different processes: sliding caused by the loss of traction of the wheel to the road surface and. so-called. deformation sliding. https://www.roneverhart.com/Nova-Medical-Phoenix-Rise-UP-Rollator-Upright-Rolling-Walker/