New trains, longer station platforms, modern signals and fresh coats of paint on bridges are included in the $5.7 billion that the LIRR stands to receive in the Metropolitan Transportation Authority’s next major infrastructure spending plan.

The projects are part of the MTA’s proposed $51 billion capital program, which will fund major infrastructure investment across the MTA’s various agencies, including the LIRR, through 2024.

Much of the LIRR’s planned spending would go toward routine maintenance and replacement of existing infrastructure, LIRR president Phillip Eng said.

“It is going to be a modernized railroad. It is going to be one that gives the railroad employees the ability to operate the way they should have been,” Eng said. “The work that has been deferred has been deferred for too long.”

The MTA Board is expected to review the plan during its meeting Monday in Manhattan and vote Wednesday whether to advance it to the state’s four-member Capital Program Review Board for final approval.

Here are highlights of what’s in store for the LIRR in the 2020-24 MTA capital program.

Stations: $910 million

LIRR stations assessed to be in the worst condition of the railroad’s 124 stations will be prioritized under the plan. Hollis, Forest Hills, Hunterspoint Avenue and Copiague will get new platforms, elevators and Braille signage. Other stations will get new station buildings, platform signage, shelter sheds, pedestrian overpasses, railings and lighting.

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The LIRR’s Mets-Willets Points station also is in line for upgrades related to the Port Authority’s plan to construct a new AirTrain between the station and LaGuardia Airport.

The budget also includes $28 million to complete the rehabilitation of the Ronkonkoma station parking garage, and $74 million in investments at Penn Station — such as HVAC upgrades, stairway replacements and other platform-level improvements — and at the LIRR’s future space at Grand Central Terminal.

The railroad said the planned spending will bring 92 percent of stations to a “state of good repair,” extend short platforms at three stations and make up to seven additional stations handicap accessible.

Tracks: $1.02 billion

The railroad’s annual “track rehabilitation program,” which is funded in the capital budget, aims to use $683 million to replace wood ties with concrete ties along up to 32 miles of track. The work will target some of the busiest segments of the LIRR system, including portions of the Main Line and the Brooklyn, Port Washington, Port Jefferson and Babylon branches.

The railroad also plans to make other improvements on its property surrounding tracks, including by addressing drainage problems in flood-prone areas, repairing deteriorated retaining walls and installing high security fencing in areas known to attract trespassers.

The railroad also plans to buy new equipment to inspect and repair tracks, including a new “track geometry car” that will fit into the new tunnels bored as part of the East Side Access project.

There’s also funding to advance the railroad’s ongoing Jamaica Capacity Improvements project, including funding to modernize Jamaica’s signal system.

Tunnels, bridges and other line structures: $343 million

The LIRR will spend $269 million on bridge rehabilitation and replacement projects. Those include replacing the Cherry Valley Road Bridge in Garden City and the Webster Avenue Bridge in Manhasset. Both new structures will be elevated to prevent truck strikes.

The railroad also will rehabilitate eight other bridges in Brooklyn, Nassau and Suffolk that have poor structural ratings. Several other bridges will be painted.

Some abandoned bridges and other structures in Queens will be demolished under the plan.

The budget also includes $75 million in funding for tunnel improvements, including along the LIRR’s Atlantic Branch between Brooklyn and Queens.

And studies conducted by outside structural engineers will assess the condition of viaducts and bridges throughout the system.

Communication and signals: $364 million

The Huntington/Port Jefferson and Babylon/Montauk branches are in line for $289 million in upgrades to their antiquated signal systems. Railroad officials said the expenditure “will target some of oldest and least-reliable signal systems across the LIRR.” The investments will bring the number of LIRR signals in a state of good repair to 69 percent, from the current 47 percent.

The plan also includes funding to advance a new “centralized traffic control” system, which would allow the LIRR to monitor its trains from a single location — improving the agency’s ability to respond to service disruptions. Currently, the LIRR monitors train movement from various towers scattered throughout its system.

The LIRR proposes to spend $75 million to improve various parts of its communication infrastructure, including through the cyclical replacement of pole lines, upgrading of fiber optics and modernizing its radio system. The investments should help train crews better communicate with dispatchers, the LIRR said.

More “Help Point” station kiosks also will be installed under the plan, as will additional cameras at some LIRR grade crossings. The railroad is also taking on a “Customer Information Technology” project that aims to address “both communication needs on a day-to-day basis and during service disruptions/service changes.”

Shops and yards: $203 million

The LIRR is looking to build new shop facilities to prepare for the expansion of its fleet and improve train cleanliness. New equipment will help repair damaged train wheels, wash trains and shops, and a new platform at Ronkonkoma will be dedicated to car cleaning.

There’s also money for maintenance facilities at the Mid-Suffolk Yard in Ronkonkoma and to study a potential new yard on the East End. The railroad will spend $84 million to upgrade employee facilities.

Power: $426 million

The little-used Central Branch, which provides a north-south link between Babylon and Hicksville, will be electrified under the plan — allowing the LIRR to reroute trains during service disruptions.

Up to five electrical substations in Queens and Nassau, which provide power to LIRR track and other equipment, will be replaced under the plan.

Other power components also will be replaced, including electrical cables and third rails, and power poles throughout the LIRR system.

Diesel trains: $242 million

To improve service for the roughly 20 percent of customers that travel to and from portions of the LIRR system that are not electrified, the railroad is planning to buy 12 new diesel locomotives and 17 coach cars. It would be the first significant addition to the railroad’s diesel fleet in more than 20 years.

LIRR megaprojects: $1.3 billion

Although not technically allotted to the LIRR — but rather to the MTA’s Capital Construction Department — the plan includes $798 million to complete the $11.2 billion East Side Access project, which will connect the railroad to a new station at Grand Central Terminal. The allotment includes funding for 160 new M9A electric train cars that will be needed to serve a projected increase in ridership.

The budget also includes $539 million to advance the construction of a new 9.8-mile-long track between Floral Park and Hicksville. The total cost of the Third Track project is $2.6 billion.

Other: $231 million

The capital program includes funding for the LIRR to replace “obsolete” security cameras throughout its system with newer technology to allow for better monitoring of LIRR facilities.

Other funds will be dedicated to environmental cleanup efforts at some locations and to help pay for independent engineers to evaluate major MTA construction projects.