The relationship between Uber Technologies Inc. and Pittsburgh, the city where its self-driving car unit is headquartered, may be taking a turn. The city's mayor Bill Peduto wants to ink a new "social contract" with the ride-sharing service.

As part of that contract, he wants Uber to sign a memorandum of understanding to offer better working conditions for its drivers, provide additional services for the elderly and improve the fuel efficiency of its cars. In an interview with The Wall Street Journal, Peduto, who was an enthusiastic supporter of Uber's initial foray into the city, said he had become "disillusioned" with the company after it backtracked on promises and fought the city government's efforts to impose a tax on ride-sharing services. (See also: The Story of Uber). 

For example, the ride-sharing service had refused to invest $25 million on a new transit connection from Carnegie Mellon to a Pittsburgh neighborhood where it was building a test track for its self-driving cars. Pittsburgh's efforts in conjunction with Uber to win the Smart City Challenge, a U.S. Department of Transportation competition with a $50 million prize, also came to naught. An Uber spokesperson told the WSJ that the company was "proud to have put Pittsburgh on the self-driving map, an effort that included creating hundreds of tech jobs and investing hundreds of millions of dollars." (See also: Smart Cities: Companies Profiting From Urban Challenges.)

Uber arrived in Pittsburgh primarily to take advantage of Carnegie Mellon University's robotics department, which is considered one the best in the country. According to the WSJ report, Uber has hired 700 people in the city. However, its partnership with the city has been a rocky one. A number of news reports have cataloged problems between the government and the service. Uber's tests of self-driving cars have also come under a cloud due to a spate of negative reports about their performance and accidents involving the cars. The Pennsylvania legislature is currently considering laws, similar to the ones in California, to regulate tests of self-driving cars. (See also: Senior Executive in Uber's Self-Driving Unit Quits.)