NEW YORK (Reuters) - A planned New York City-New Jersey train tunnel under the Hudson River will add an average $19,000 to homes within two miles of stations and could ease financial strain on local governments, a study showed.

The new rail tunnel, the first in decades, will prove an even bigger windfall for homeowners who are within walking distance of train stations as their property values should rise by an average of $29,000, the report said on Thursday.

The rise in property values could ease financial strain on counties, cities and towns by giving them an extra $375 million in property taxes, according to the study by the Regional Plan Association, a research and advocacy group for the New York, New Jersey and Connecticut metropolitan area.

That tax forecast assumes home values rise by a total of $18 billion.

New Jersey's property taxes are among the nation's highest. Though Republican Governor Chris Christie persuaded state legislators to cap this levy, they have balked at other curbs he proposed, which would, for example, squeeze public workers' paychecks and benefits.

The new $9 billion Hudson River tunnel is meant to cut overcrowding at New York City's midtown Pennsylvania Station and is not expected to be finished until 2018. The Regional Plan Association based its forecasts on two previous rail improvements for commuters who live west of the Hudson.

The new Hudson tunnel, called Access to the Region's Core, will make it easier for people to commute by rail to Manhattan, where jobs often command higher salaries. It will reduce pressure on crowded tunnels and bridges used by motorists.

The number of people who live within a 50-minute train trip to midtown Manhattan will double after the new tunnel opens, the report said. The population that is within a 70-minute radius will increase by 25 percent.