# Review on Soft Mobility Infrastructure Design Codes
## 1 Introduction  
As urbanization and transportation modes continue to change and develop, many derivative problems are raised [1]. A US study shows that from 1982 to 2011, the total traffic congestion time in the top 101 major cities in the United States increased by 4.8 billion hours [2]. At the same time, traffic congestion may further aggravate environmental pollution, such as greenhouse gas emissions [3]. However, environmental pollution can also cause people's health problems [4]. In this context, infrastructure for soft mobility has become a key focus in the field of urban planning and sustainable transportation. Soft mobility encompasses non-motorized transportation, including walking, cycling, roller skating, and skateboarding. It can also be viewed as \"zero-impact\" mobility. While terms to describe this mode of movement are not standardized yet, phrases like \"soft mobility\", and \"slow traffic\" are used interchangeably, primarily emphasizing pedestrians and cyclists as alternatives to cars [5]. Walking and cycling complement and connect with each other. A walk will inevitably follow before and after the ride. Cycling and walking therefore share similar advantages and contributions to society. Taking cycling as an example, it has many advantages for both cyclists and society: it is a low-cost, low-polluting, health-improving way to travel [6]. Cycling is more space-efficient than car transport, environmentally friendly, and requires minimal investment (excluding professional sports). Operational costs are negligible as bicycles do not need fuel, and expenses like energy beverages for cyclists do not significantlyimpact on the overall cost. Additionally, cycling offers door-to-door transport, unlike public transportation [7]. Especially during COVID-19 pandemic outbreaks, cycling in an open-air environment can avoid crowds gathering while providing a good ventilation environment, which is conducive to the dissipation of the virus and protects people's health [8]. The resilience of cycling infrastructure has emerged as a critical component in fostering sustainable urban mobility. Firstly, enhancing infrastructure design to prioritize road safety is imperative, particularly for vulnerable road users who disproportionately bear the risks of traffic accidents. For instance, segregated bicycle lanes with physical barriers (e.g., bollards or curbs) and optimized intersection signals can reduce conflicts with motorized traffic, thereby lowering injury rates. Secondly, economic sustainability must be embedded in lifecycle planning. Integrating quality standards into regulations ensures long-term maintenance efficiency and cost-effectiveness [9]. Prioritizing durability during the design phase can reduce long-term fiscal burdens while maintaining operational integrity. Notably, cycling infrastructure has proven to be a resilient alternative during crises. The COVID-19 pandemic highlighted its adaptability, with cities especially in South Korea and Japan observing a modal shift from public transit to bicycles [10; 11]. Temporary infrastructure expansions, such as emergency bike lanes, not only accommodated increased demand but also alleviated pressure on overwhelmed transport systems. This dual role--serving daily commutes and emergency mobility--underscores cycling infrastructure's capacity to enhance systemic resilience, ensuring continuity during disruptions while advancing climate-responsive urban agendas. While human-driven transportation is one possibility, it does not encompass all soft mobility modes, necessitating other alternatives powered by pure energies. Electric-powered two-wheelers, like e-scooters and e-bikes, serve as such alternatives [12]. E-scooters have recently emerged as a promising sustainable mode for urban trips, and their popularity is rapidly growing across the world [13]. They may be used either for short door-to-door trips or for first- or last-mile connections to public transport stops and stations. They may be privately owned or part of large, shared fleets.