Metro-North Railroad last Friday combined and eliminated 29 trains on its New Haven line, serving Stamford, New Canaan, Norwalk, Darien and other area towns. Additional stops were added on some runs to accommodate riders at other stations, as the railroad reined in service because of fewer riders.

During the morning peak, a total of 23 trains were combined and eliminated, and off-peak service to New Haven line destinations ran hourly from noon to 3 p.m.

Ridership during the morning peak before 9 a.m. fell 65 percent system-wide, and 56 percent on the New Haven line, Metro-North spokeswoman Marjorie Anders said.

While cutting back on service helps protect some of the railroad's aging M-2 fleet from piling up snow-related damage and downtime, it also brings a blizzard of extra operating costs, Anders said.

Keeping trains from breaking down during snowstorms, and being ready to handle emergency track and equipment repairs during inclement weather, entails significant costs on days when the railroad loses a large percentage of ticket revenue, Anders said.

"There is no cost savings during a snowstorm," Anders said. "The main benefit of reducing service is to protect the equipment during storms and avoid running the service when ridership falls by 50 percent or more."

Much of the cost of snowstorm preparations and keeping the service running is in labor, Anders said.

Metro-North has allotted $58.3 million for overtime in 2010, and $84.6 million for materials and supplies, according to the 2010 railroad budget, two budget areas that would be padded by snow removal costs, MTA spokesman Kevin Ortiz said.

The railroad doesn't budget money for snow removal, but diverts whatever funding is necessary to keep the system working, Anders said.

Among the additional costs of operating during a snowstorm are paying crews to de-ice station staircases and platforms, dispatching large landscaping crews to remove fallen trees, and in some cases, welders to fix damaged rails by trees or other weather-related problems, Anders said.

"Sometimes, if it is a big enough tree, it will crush the third rail, and we have to send out crews to replace it, including a welder who would usually be engaged in more productive activities," she said. "There are lots and lots of extra costs associated with a snowstorm."