A proposal to manage the city’s subways more like a system of independent railroads would be hampered by so many built-in centralized features, experts warned yesterday, that riders should not expect to see major improvements in service.

In an effort to improve the timeliness, cleanliness, and safety of its trains, Metropolitan Transportation Authority officials said yesterday they would consider appointing independent managers to run all 24 subway lines more like competitive, private companies. Managers would compete to provide the cleanest, safest, and most punctual trains, officials said. They would be rewarded or punished, possibly financially, based on the level of their train line’s performance.

The plan immediately was greeted with skepticism by lawmakers and transportation experts, who said a common capital budget, shared stations, and a single operations planning department would make it difficult for train lines to operate as independent entities. “Lines still share stations, tracks, and capital investment,” a fellow at the Manhattan Institute, Nicole Gelinas, said. “If the MTA doesn’t have enough money to invest in its assets, that affects all lines; they’re not going to have their own access to tax dollars and bond financing.” When flooding affects multiple train lines, it would be difficult for the line managers each to deal with the problem independently, she said.

Assemblyman Richard Brodsky, a Democrat of Westchester who is chairman of an MTA oversight committee, said it was unlikely riders would see a radical improvement in service. “There’s no way that you can rearrange structures and make fundamental differences in the way the system operates,” Mr. Brodsky said. “The benefits will be marginal.”

A former chairman of the MTA, Richard Ravitch, yesterday compared the reorganization of New York’s subway system to the transit system in London, where private companies run train lines. “The cars here are much more fungible because we have two major maintenance yards,” Mr. Ravitch said. “It’s harder to do here, but a very important effort.”

The pilot program on the L and no. 7 lines is scheduled to begin Monday. It is fully funded by the current operating budget, officials said.

“It doesn’t make sense for every little decision to go to 347 Madison Avenue,” Council Member John Liu, who heads the council’s transportation committee, said, referring to the MTA’s Midtown headquarters. “It’s a more entrepreneurial approach.”