Train ridership in the Northeast rail corridor is expected to rise 53 percent by 1981 a top federal railroad regulator says.

Federal Railroad Administrator John Sullivan said at House Government Activities and Transportation Subcommittee hearings yesterday that 14.8 million people are expected to ride the rails between Boston and Washington annually by 1981. By 1990 that number should swell to 21.8 million, he added.

Sullivan's comments came in response to the opening remarks of subcommittee Chairman John Burton (D-Calif.) who opened the hearings Thursday with a scathing description of the failures of federal attempts to improve rail operations in the Northeast.

Burton placed some of the blame on Transportation Secretary Brock Adams, who supported creation of the Railroad Revitalization and Regulatory Reform Act, which two years ago provided nearly $2 billion for the Northeast Corrider Improvement Project, involving Amtrak, Conrail and local commute operations.

Burton cited "confusion, duplication and endless delay" for steering that Project "onto a costly sidetrack." And Adams has not done anything to get the project back on its feet, he added.

In his remarks yesterday, Sullivan admitted that completing improvements in the Northeast by the target date of 1981 now does "not seem probable." But he said the goal of a 2-hour and 40-minute trip between New York and Washington would be met by then.

And much of the track work and other basic improvements should be completed in time, Sullivan added, although he said there still would be delays between New York and Boston because state projects are slowing federal efforts.

"Both the president and the secretary (of Transportation) are firmly committed to rail service improvements in the corridor," Sullivan said. "These improvements and the jobs associated with them are vital to the economy of the Eastern Seaboard."

Sullivan also testified that the increase in rail ridership would contribute significantly to a desired lessening in energy use and a reduction in traffic congestion in the Northeast Corridor. He said that gasoline accounts for three-fourths of all energy used for transportation there.

"A major goal of the project is to get people out of their cars and onto public transportation," Sullivan said.

"I have the utmost confidence in our staff's ability to successfully implement the Northeast Corridor Project where the objective is to achieve a level of passenger service never before experienced in the United States," Sullivan added.