Commuter railroad strikes in New York City and now Philadelphia are a result of shifts in ownership from private to quasi-public to public. Each shift resulted in a greater awareness of the huge, built-in costs of running the systems.
The quasi-public corporation, Conrail, took over operations that private owners gave up as unprofitable. Conrail found that it could not cut costs, particularly those that were deeply embedded in labor contracts with 17 unions. These involved costly work rules, such as those governing crew sizes, negotiated during more than 50 years of bargaining with vulnerable private railroads.
A year ago, the federal government, at the direction of President Reagan and with the acquiescence of Congress, did away with Conrail's passenger operation. State and local agencies were forced to take over commuter rail lines.
At the same time, the federal government complicated state and local operation of commuter rail service:
* Washington did not give states absolute jurisdiction over the railroads' labor relations, retaining just enough overseer authority to keep states from barring walkouts by invoking laws that make public employee strikes illegal.
* It also began reducing federal railroad subsidies to commuter carriers and planned the elimination of all contributions by 1985.
The present strikes, inconveniencing more than 200,000 daily commuters, involve New Jersey Transit, with 70,000 riders; the Metropolitan Transportation Authority (MTA), 85,000; and the Southeastern Pennsylvania Transportation Authority (SEPTA) in Philadelphia, 50,000. The same union, the United Transportation Union (UTU), is involved in each dispute.
Although wages are involved, the commuter-line walkouts are centered more on work rules and practices, issues that are always difficult to settle because workers would have to give back gains won in the past.
SEPTA in Philadelphia wants to reduce its work force by about 400 through a much wider use of part-time workers. This issue was raised in 1981 and was a major factor in a 19-day strike that ended when Conrail gave up on the issue.
In New Jersey, where slow progress is reported from bargaining rooms, NJ Transit wants to eliminate or reduce payments for unworked hours between morning and late afternoon rush-hour shifts. Now conductors and trainmen are paid for four hours or more while they wait for resumption of commuter runs.
The New York MTA strike involves the number of conductors and trainmen needed. The agency wants to cut operating costs by laying off at least 70 crewmen (the UTU says that the number might be as many as 152). UTU says that it cannot give the MTA ''an unbridled right'' to reduce crews.