Abstract: More and more people choose cycling for both leisure and commuting due to the subjective pursuit of healthy working styles and changes in life philosophy, or due to the objective continuous improvement of cycling environment and facilities. Cycle commuting has multiple benefits, including realizing the goal of low-carbon transportation, improving air quality in cities, and strengthening the physical and mental health of residents. Therefore, it is of vital importance to build a well-developed cycle commuting network. Urban greenways act as a medium between people and urban spaces. Building cycling greenways based on urban greenways is a recommended choice. At present, cycling routes are still built according to the existing greenland system and most are for leisure purposes. Effective guidance does not presently exist for the planning of a cycle commuting system. Therefore, it is important to study the integration of cycle commuting network systems based on existing greenway systems.
　　The Jiangtai-Jiuxianqiao area in Beijing, which has a dense distribution of employment sites and a high demand for cycle commuting, was selected as the study area. The Wangjing area on the north side is a Class II employment center in Beijing, second only to the CBD, Financial Street, and Zhongguancun areas. Cycling and public transport are two major commuting modes for people in the area. Most cycle commuting behaviors involve mid- and short-distance commutes of less than 5 km and there is a demand to further explore the potential of cycle commuting. According to questionnaires and research, cycling commuters are the least satisfied with the safety and comfort of cycling in the area, and there are strong perceptions that influence cycling greatly, including road slope and greenery along the streets.
　　The objects connected to the cycle commuting routes in the region are divided into commuting demand ends and attraction ends according to their functional characteristics, with a cycling origin (point O) and a cycling destination (point D). The demand node includes the residential agglomeration zone and transport agglomeration zone. The attraction node includes the office building agglomeration zone, education agglomeration zone, medical agglomeration zone, and recreational resources. Regions with demands and attractions in the study area were screened to determine important nodes of cycle commuting routes. Moreover, an optimal path analysis was carried out through the GIS network analysis method. The potential commuting routes in the study area were screened according to number of repetitions. In addition, three types of elements, including motor and non-motor vehicle separation degree, intersection density, and speed limit, were combined and weighted as an evaluation index of cycling safety within the study area. Moreover, slope, tree density at roadsides, and road grade were combined and weighted as an evaluation index of cycling comfort in the study area. With comprehensive consideration to the above safety index, comfort index, and field survey, the potential commuting routes in the optimal path analysis results were extracted as the prior path for cycle commuting.
　　Based on three basic principles of accessibility, safety, and comfort, the corresponding optimization strategies were proposed, including connecting nodes, perfecting networks, separating lanes and flows, complete equipment of facilities, enriching activities, and so on. In practical construction and reconstruction, it is suggested to construct cycle commuting routes gradually according to importance, and to perfect sections using the corresponding optimization strategies in accordance with their characteristics. 
　　A complete cycle commuting network is very important to promote the sustainable development of cities. In this study, cycling routes and environments in employment centers were analyzed and improved, aiming to improve the engagement of citizens with cycle commuting and increase the use of routes. This study can provide an analytical method to perfect the cycle commuting networks of cities to achieve greater social outcomes with limited financial investment.

Key words: greenway, cycle commuting routes, network analysis, cycling environment

摘要： 当下骑行绿道建设主要依据现有绿地系统进行建设，缺乏与通勤骑行体系建设的整合研究；规划实施中也面临具体骑行线路优先级的排序和针对性策略如何选择的难题。以北京“将台-酒仙桥”就业地区为对象，通过基于通勤骑行需求强度（CCD）与吸引强度（CCA）的通勤绿道节点识别，利用GIS网络分析法对区域内的绿道进行最优路径分析；以最优路径重复次数结果为主要依据，并结合路段安全性与适宜性评估以及实地调研情况，提出最佳通勤骑行线路网络。优化后的网络融合现有绿道，更具综合性，有助于提升通勤绿道使用率；提出通达性、安全性、舒适性方面的骑行系统优化策略，更具针对性，有助于完善北京城市就业地区通勤骑行网络和提升其骑行环境。

关键词: 绿道, 通勤骑行线路, 网络分析, 骑行环境