阐述代步工具的概念和发展史,阐述可用性设计的概念和设计原则,并以之为指导分析城市居民对于代步工具的设计需求,提出相应解决方案。 Explain the concept and development history of transportation tools, elaborate the concepts and design principles of usability design, and use it as a guide to analyze the design requirements of urban residents for the means of transportation and propose corresponding solutions.