Stagnant ridership revenue and increased costs made the fare raises inevitable, according to an authority spokesman.
Livingstone, who has made the "fare deal" promise the centrepiece of his campaign, called on Johnson to outline his policies on fares for the next four years.
"No matter how you classify it, selling swipes is illegal and makes the fare more expensive for all law-abiding transit riders," Kevin Ortiz, an authority spokesman, wrote in an e-mail.
A critical problem, Mr. Masten said, is that the recent ad blitz promoting the various menu items being sold for a dollar has made the fare at the restaurants "synonymous with 'value' meals, which drives sales but lowers the value of the McDonald's brand".
So Mr. Bloomberg's proposal could still be costly, said Robert E. Paaswell, the director of the University Transportation Research Center at the City College of New York".Whether you make it free or make the fare $10, it costs so much to run a bus," Mr. Paaswell said.
Amtrak, which has been offering up to 25 percent off Northeast Regional fares since February 2009, is making the discount fares permanent for travelers who book 14 days in advance.
And as part of Amtrak's Winter Promotion, there is a free companion fare along those same routes, making the New York-Atlanta fare equal to $42 a person, for two passengers.
Since then, Ferry company CalMac (calmac.co.uk) has scrapped all charges for bikes and reduced its fares, making the trip even cheaper.
The city also reached an agreement with its taxi fleet: All taxis within the city will have to be electric by 2025 and, during the transition, electric taxis are getting preferential treatment at certain city taxi stands, so they have to wait less for their fares, making the switch to electricity more profitable.
In its last two years of operation, wartime rises in costs made the fixed fare structure untenable, and between July 1939 and January 1941 there were five slight adjustments to the fares.
