On-demand transportation services such as Uber and Lyft have emerged as another pivotal application of sensing, connectivity, and AI, with algorithms for matching drivers to passengers by location and suitability (reputation modeling). 
Through dynamic pricing, these services ration access by willingness-to-pay, with dynamic pricing also encouraging an increase in the supply of drivers, and have become a popular method for transportation in cities. With their rapid advance have come multiple policy and legal issues, such as competition with existing taxi services and concerns about lack of regulation and safety. On-demand transportation services seem likely to be a major force towards self-driving cars.
Carpooling and ridesharing, more generally, have long been seen as a promising approach to decrease traffic congestion and better utilize personal transportation resources. Services such as Zimride and Nuride bring together people sharing similar routes for a joint trip. But this approach to carpooling has failed to gain traction on a large scale.
 Jared Meyer, "Uber and Lyft are changing the way Americans move about their country," National Review, June 7, 2016, accessed August 1, 2016, http://www.nationalreview.com/article/436263/uber-lyft-ride-sharing-services-sharing-economy-are-future.
 Alexander Howard, "How Digital Platforms Like LinkedIn, Uber And TaskRabbit Are Changing The On-Demand Economy," The Huffington Post, July 14, 2015, accessed August 1, 2016, http://www.huffingtonpost.com/entry/online-talent-platforms_us_55a03545e4b0b8145f72ccf6.