A fledgling plan to offer fare-free rides on O'ahu's public buses ran into stiff opposition yesterday from some tour bus and taxi operators who said it could hurt their businesses and some riders.

Tourists would likely take advantage of free rides to visit attractions such as Hanauma Bay, cutting into tour bus revenue and leaving public buses overcrowded, said Katsumi Tanaka, chairman and CEO of E Noa Tours.

"There isn't enough service currently for those who are denied the wonderful bus," he said.

Dale Evans, president of Charley's Taxi, said she worried the plan would take money away from transportation services for disabled riders.

Honolulu City Council chairwoman Barbara Marshall, who proposed the free rides, said they should be considered as a way to promote public transportation and relieve traffic congestion.

O'ahu should consider such alternatives before spending $5 billion or more on a new mass-transit system, Marshall said.

"This is something we could do fairly immediately," Marshall said.

Ridership on the Big Island's smaller bus system has soared since fares were suspended there two years ago, she said. The adult fare for a single ride on O'ahu's system is $2.

The plan would cost about $40 million per year in lost fare revenue, Marshall said.

A council panel tentatively advanced a bill that would allow fares to be suspended if a future annual budget can be balanced without the fare money.