The Long Island Rail Road’s 355,000 daily riders will pay as much as $15 a month more to ride the train under the MTA’s latest fare and toll increase approved Wednesday.

The rate hike — which is the MTA’s sixth since 2008 — averages out to about 4 percent for railroad commuters, subway and bus riders, and drivers crossing the agency’s bridges and tunnels. But some will see significantly larger hikes, while others will see none at all when the new fares and tolls take effect on March 19.

To limit the pain for LIRR riders, who pay some of the highest fares in the nation, the Metropolitan Transportation Authority capped increases on monthly tickets to $15, meaning commuters traveling farthest, including from Riverhead and Montauk, will pay about 3 percent more. But other ticket types, such as certain one-way tickets within New York City stations, will climb as much as 6 percent in order to keep the hikes to 25-cent increments.

LIRR officials have said the majority of riders will see increases of 3.75 percent or less. MTA chairman Thomas Prendergast, presiding over his last board meeting before retiring later this month, said the hikes were kept “as small as reasonably possible” but remain a “necessary part of the MTA’s financial plan.” The increases are the smallest since the agency adopted a schedule of biennial hikes in 2009.

Hicksville commuter John Brooks said the $297 he will pay for his monthly ticket is “a lot of money,” but the increase is reasonable given several proposed improvements the LIRR is planning, including a major renovation of Hicksville and Penn stations and the addition of a third track on the Main Line.

“If they are implementing those changes, I guess the cost is justified,” Brooks, 31, an ironworker, said. “Unfortunately, our salaries stay the same.”

advertisement | advertise on newsday

LIRR monthly commuters will see the increase in their April ticket.

MTA Board member Mitchell Pally of Stony Brook commended the authority for setting the $15 cap on commuter railroad tickets — noting that adhering strictly to a percentage increase has, in the past, effectively punished Suffolk commuters.

“It’s not a percentage. It’s a dollar amount. And while in some places that dollar amount may be very small in number, in many places that dollar amount is very large in number . . . when you’re already paying two, three, sometimes four hundred dollars a month,” said Pally, who called the $15 cap “more reasonable.”

Much of the debate over the fare plan at Wednesday’s Manhattan meeting focused on the MTA’s decision to keep the cost of a single bus or subway ride at $2.75, while reducing the size of the bonus applied to a future transit fare purchase to 5 percent, from the current 11 percent. Another plan rejected by the MTA would have raised the fare to $3, but also increased the bonus to 16 percent. Prendergast said the MTA went with the option that would protect its lowest-income riders, who are more likely to pay for a bus or subway ride in cash.

Also under the new fares, LIRR weekly tickets will not go up by more than $4.75 for the longest trips, and increases on one-way tickets will not exceed 50 cents. The cost of a monthly MetroCard goes up to $121 — an increase of $4.50.

Tolls on major crossings for most E-ZPass customers will increase by less than 25 cents and by 50 cents for cash customers.

The MTA also announced that it will conduct a “field study” to determine the feasibility of providing discounted LIRR fares for some New York City residents in areas with few transit options, including in Southeast Queens. The so-called “Freedom Ticket” will be tested on certain trips made to and from Atlantic Terminal in Brooklyn.