Librado Romero/The New York Times

The cost of crossing the bridges and tunnels that span the Hudson River to New York City could rise by 50 percent for many drivers under a steep series of toll increases to be proposed on Friday by the Port Authority of New York and New Jersey, according to two people familiar with the plans.

A $4 toll increase for E-ZPass users could go into effect as soon as September on the three major Hudson River crossings – the George Washington Bridge and the Holland and Lincoln Tunnels – as well as three other bridges between New Jersey and Staten Island, the Bayonne and Goethals Bridges and the Outerbridge Crossing.

The proposal, the first increase since 2008 and only the third since 2001, would raise peak-hour E-ZPass tolls on those crossings to $12 a ride, up from $8. The individuals familiar with the plans asked to remain anonymous because the proposal was not yet intended to be made public.

The biggest increase by far would be felt by drivers who pay in cash: cash tolls on those crossings would be raised by $7, to $15 a trip. (By comparison, a cash toll on the Verrazano-Narrows Bridge currently costs $13.) About 25 percent of drivers on the Port Authority crossings currently pay in cash.

A single fare on the PATH train, the diminutive commuter subway system that connects parts of Manhattan to New Jersey, would be raised by $1, to $2.75 a ride.

And the price of a 30-day unlimited pass for the PATH system would be raised by 65 percent, to $89 from $54 a month.

The proposal calls for the crossing tolls to be raised again in 2014, with another planned increase of $2 for drivers who use E-ZPass and on the cash toll. The PATH fare would not be raised again in 2014, under the current proposal.

Rumors of a toll hike have been floating around transit and political circles for months. But the increases unveiled on Friday are significantly steeper than expected: planners at the Port Authority had originally been discussing a $2 raise in the tolls this year.

The board of the Port Authority must approve the proposal at a meeting this month. If approved, the governors who oversee the cross-state agency, Gov. Andrew M. Cuomo of New York and Gov. Chris Christie of New Jersey, would have a 10-day period during which they would be allowed to veto the toll increase.

Revenue from the first set of higher tolls would raise an additional $720 million for the agency, which controls many of the region’s bridges, tunnels, shipping ports and airports. The second phase, in 2014, would raise an additional $290 million.