# Study on the Minimum Operation Width of Human-Powered Bicycles for Safe and Comfortable Cycling
###### Abstract  
Chinese cities are increasingly developing exclusive bicycle paths to improve the safety and efficiency of bicycle transit. The width of bikeways is a critical factor influencing cyclists' safety and comfort, with insufficient width identified as a major contributor to bicycle accidents. Therefore, determining the minimum operational width for human-powered bicycles is essential for bikeway design. While some countries' design manuals consider speed as a factor in determining width, there is a lack of field experiments to validate these specifications from the perspective of cyclists' safety and comfort. This study addresses this gap by conducting a field experiment to measure cycling workload, which reflects safety and comfort under different widths and cycling speeds. The experiment involved 12 cyclists on a test road, where cycling workload was measured at various preset widths and cycling speeds for a single human-powered cyclist. The results were further validated using conventional lateral distance measurement techniques, which are used in the existing literature to determine the cycling width. The results show that wider bikeway widths lead to a lower cycling workload, enhancing comfort and safety. However, both very high (over 20 km/h) and very low (under 5 km/h) speeds significantly increase cyclists' workload, which in turn requires a wider path to maintain a safe and comfortable cycling experience. The study found that a minimum width of 0.90 m may be adequate for cyclists traveling at speeds between 10 and 15 km/h, while a width of 1.0 m is sufficient for speeds ranging from 5 km/h to 25 km/h, provided the bicycle width does not exceed 0.62 m. Given that cyclists typically progress from slower to faster speeds, a minimum operational width of 1.0 m is recommended for most cases. This study highlights the importance of considering cyclists' workload in determining appropriate bikeway widths. It provides valuable insights for designing safer, more comfortable bike paths and reducing bicycle accidents, contributing to the sustainable development of urban cycling infrastructure. c 2024 14 10928 10.3390/appl/142310928 10.3390/appl/142310928 10.3390/appl/142310928 10.390/appl/142310928 10.  
bikeways exerts a qualitative and substantial influence on a multitude of factors shaping cyclists' safety and comfort, as evidenced by numerous pertinent studies. These factors encompass various dimensions, including hindrances such as conflicts, crashes, delays, detours, disturbances, and associated risks [8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18]. Moreover, considerations of service quality, encompassing metrics like bicycle level of service, capacity, safety ratings, bikeability, perceived invitingness and comfort, as well as satisfaction levels, are pivotal [19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29]. Additionally, factors relating to cyclists' behavior such as lane-keeping/change, lane-travel speed, and passing distance [30; 31; 32; 33; 34; 35], further underscore the significance of bikeway width. As vulnerable road users (VRUs), cyclists are exposed to environmental factors and road infrastructure. The operational conditions and safety issues of bicycle traffic, as well as its compatibility with road infrastructure and other traffic components, have garnered significant attention from researchers [36; 37; 38]. The narrow width of bikeways can lead to cyclists experiencing feelings of insecurity and discomfort and may cause them to sway more to stay balanced. This increases the close passing distance and the risk of collisions with other road users and roadside infrastructure, thereby posing significant safety risks. According to the related research, one of the primary factors contributing to bicycle-motor vehicle collisions, which possess the highest fatality rates among bicycle accidents, is the inadequate width of bikeways [39]. It is reported that single bicycle crashes account for approximately half of all bicycle accidents [40; 41].