However, things might change over the next few months; New York City's Taxi and Limousine Commission is proposing Uber and other credit card payment ride services allow the option to tip electronically.
"This rule proposal will be an important first step to improve earning potential in the for-hire-vehicle industry, but it is just one piece of a more comprehensive effort to improve the economic well-being of drivers", said Commissioner Meera Joshi in a statement.
Delhi commuters will need to brace up for a no-show of taxis and autos on Tuesday as a total of 13 associations of app-based taxi and auto-drivers will observe a day-long strike against their partners Ola and Uber. He continued, "Uber is always striving to offer the best earning opportunity for drivers and we are constantly working to improve the driver experience".
Lyft, Uber's biggest competitor in the United States, already offers passengers the option to tip drivers through its app.
The rule could have implications in other cities where Uber operates.
Ever since Uber agreed to recognize the IDG as its drivers' representative last May, the group has put tipping at the top of its demands-and gotten nowhere.
Uber's refusal to launch an in-app tip option led the guild to launch a campaign a year ago with auto stickers and social media posts to let passengers know that they can tip and that gratuity is not included in their fare. It announced in March that drivers had earned an extra $200 million in income from tipping since the feature was introduced.
Delhi-NCR residents got their first taste of Ola and Uber drivers' strike against the cab companies in February this year, which went on for nearly two weeks.
Justice Rajiv Sahai Endlaw passed a decree "permanently injuncting" the two unions and anyone associated with them from blocking Ola and Uber taxis.
The company, which operates in 74 countries, says it now has 147,000 drivers on the Uber platform in California, accounting for almost one-fourth of its US total. Some 41% of respondents say close proximity to the server/cashier while entering a tip amount would make them more likely to tip, the 2015 Software Advice study found.
"People do want to tip", he said.
Uber spokeswoman Alix Anfang said the company will review the proposed rule once it's drafted.
"Uber led drivers and passengers alike to believe that fares would match what was lost in gratuities", he said. After that, the commission's board will cast its vote.