Large-scale nationwide ridesharing system: A case study of Chunyun

Abstract

In this paper, we propose a large-scale nationwide ridesharing system named CountryRoads, which is designed to resolve the surge of homeward-bound persons during holiday seasons. CountryRoads matches drivers who are willing to share their spare seats with passengers who are unable to obtain public transportation for long-distance trips. The system utilizes a variety of user interfaces, including text messages, mobile websites, and smart-phone applications to enable the participation of a variety of people. Further, it implements an online greedy-matching algorithm to solve the ridesharing problem in order to propose matches between drivers and passengers. We deploy and evaluate CountryRoads during the Chinese Spring Festival travel season (Chunyun period), when all forms of transportation are stressed or near saturation, and when many lower-income individuals fail to reserve seats for rail or flight trips. We present our design choices, analytics, and lessons learned from our multi-year deployment in 2012, 2014, and 2015. The improvements over the years resulted in up to 17,272 users, 4777 ridesharing tuples, and an eventual success rate of 23.2% in 2015. This is a significant result considering that most of our participants use CountryRoads as a last resort in response to public transportation shortages.

Keywords

• Ridesharing
• Matching algorithms
• Deployment experiences