Unreliability of Delay Caused by Bike Unavailability in Bike Share Systems

The recent proliferation of bike share operations has augmented established docked systems in major cities with several stationless operators. By relaxing control of where the bikes may be located, the stationless systems are more agile but less certain. We hypothesize that a stationless bike share system reduces access and egress distance while increasing unreliability, offering a trade-off from the customer’s perspective. This work presents a framework for quantifying the trade-off between expected trip time and variability in trip time for stationed and stationless bike share systems. The systems are modeled subject to shared assumptions where possible, and the trade-off is measured for about 1,000 simulated journeys corresponding to a 1 h simulation. Sensitivity to the shared assumptions is tested to support the generalizability of the results. The findings indicate that stationed systems have higher expected user costs and lower variance in user cost. As expected, the user cost distributions are asymmetrical. This analysis supports the context-specific adoption of stationed or stationless bike share operations based on user attributes (trip purpose, walk speed, destination choice, etc.) and operator attributes (budget for bicycles, support for public transport, value on reliability, etc.).