Bus passengers should keep their eyes on more than their timetables Friday. The future of Long Island Bus service is at stake as the Nassau County Legislature votes on the 2011 budget.

County Executive Edward Mangano, citing financial straits, has earmarked only $9.1 million for LI Bus in the proposed $2.64 billion budget. With the MTA potentially withdrawing $26 million in subsidies, the vote may be a precursor to privatizing the system.

“A $9.1 million contribution would leave Long Island Bus a shell of its former self,” said Ryan Lynch, a senior planner with Tri-State Transportation Campaign.

TSTC and Vision Long Island suggested some $26 million in budget shifts and new revenue to make up for the loss of MTA funding.

Aaron Donovan, an MTA spokesman, said Nassau County’s contribution has dwindled over the past decade from $21.8 million in 1999. “We can no longer afford to subsidize Long Island Bus,” he said.

Ultimately, the MTA has until December to set their funding levels. “We hope this isn’t a game of chicken with bus riders in the middle,” Lynch said, noting the strained relationship with the county.