###### Abstract  
The jobs-housing imbalance and long commuting distances for residents in many megacities in China are promoting the increase in mode share with rail transit. The emergence of free-floating bike sharing (FFBS) provides an attractive and cost-effective multi-modal solution to the first/last mile problem. This study identifies the mobility patterns of free-floating bikes as a feeder mode to 277 rail transit stations in Beijing using detailed GPS data, and the relationships between these patterns, culture and spatial layout of the city are examined. The results show that the distribution of free-floating bikes, as a feeder mode to rail transit, exhibits an aggregating feature in the spatial-temporal pattern on weekdays. According to the results of the Clusters method and ANOVA analysis, the operation characteristics of free-floating bikes are related to the location of the transit station and the job-to-housing ratio around that area, and imbalanced usage of shared bikes across the city may result from the extreme values of job-to-housing ratios. Based on the fitted distance decay curve, accessing distance is greatly influenced by urban morphology and location. Based on these findings, recommendations for planning, management, and rebalancing of the FFBS system as a feeder mode to rail transit are proposed to promote the integration of FFBS and the rail transit system. free-floating bike sharing operation characteristics; GPS data; rail transit; integration Article  
[PERSON], [PERSON], [PERSON] Operation Characteristics of a Free-Floating Bike Sharing System as a Feeder Mode to Rail Transit Based on GPS Data  
Data. _Appl. Sci._**2022**, _12_, 8677. [[https://doi.org/10.3390/app12178677](https://doi.org/10.3390/app12178677)]([https://doi.org/10.3390/app12178677](https://doi.org/10.3390/app12178677))  
Academic Editor  
[PERSON]  
Received: 8 July 2022  
Accepted: 27 August 2022  
Published: 30 August 2022  
**Published:**  
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some cities, the number of shared bike riders has grown progressively compared with other transport modes [11; 12]. Residents may choose the bike-sharing mode to avoid public transport and maintain social distance. Despite the changes in user volume, usage patterns, and motivations [13; 14], the bike-sharing mode is considered the most robust and resilient transportation option during the post-coronavirus era [15] and is an area of strong research focus. There are two main types of bike-sharing systems: station-based bike sharing (SBBS) and free-floating bike sharing (FFBS). FFBS does not have fixed dock stations. Thus, expensive construction costs for stations and kiosk machines can be avoided. Users can unlock the shared bikes by simply using their smartphone, and the bikes can be left anywhere in public for the next user. Compared with SBBS users, the average walking distances of FFBS users are shorter. People can track down bikes nearby before the trip by checking the mobile app whenever they need service, which frees them from worries regarding whether there are bikes available in the public bike station. When reaching the destination, users can leave bikes near the destination without concerns about potential shortages of vacant spots in the station, which is attractive for commuters with limited time and travelers new to the area [16; 17]. However, new problems also occur, such as illegal parking, vandalism, and imbalance problems. Due to the imperfect management and inadequate regulations, the expansion of bike sharing occupies limited urban spaces, adding to the congestion and the decline in the quality of urban space. The uneven distribution of FFBS flows also results in imbalance problems, making it difficult for users to find available shared bikes during peak hours.