一个是城市步行道的日益流行造成拥挤和使用者间的矛盾，特别是在骑车、步行、轮滑和骑马的人之间。

One was the growing popularity of urban trails, which led to crowing and user conflicts, especially among cyclists, walkers, in-line skaters and equestrians.

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从而为优化步行轮主要参数和预测步行轮的牵引附着性能提供了理论依据。

Whereby it is able to optimize the major parameters and to predict the kinetic performance of the walking wheel with the results studied.

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