The LIRR third-track expansion project has moved swiftly since Gov. Andrew M. Cuomo announced it Jan. 5, 2016. In November, project officials published a draft environmental impact statement, which will be the subject of six public hearings in Westbury, Hempstead and New Hyde Park from Jan. 17 - 19. .

The LIRR is already evaluating potential contractors for the project, and expects to begin construction this year.

As the project progresses, here’s a review of the basics:

What is the third track?

The LIRR Expansion Project, as it’s officially called, aims to construct a 9.8-mile long third track between Floral Park and Hicksville. Officials have said it has the potential to be the largest public works project on Long Island in decades.

What will it do?

Benefits of a third track include allowing the LIRR to more easily bounce back from service disruptions on its Main Line, and providing enough capacity to run extra trains, including for riders going in the reverse direction during rush hours, project officials say. Supporters also say the project will increase property values and create jobs on Long Island.

advertisement | advertise on newsday

What’s it going to cost? How long will construction take?

The estimated budget is $2 billion, and officials say construction will take three to four years. The MTA expects to amend its existing 5-year, $29 billion capital program, to make room for the project. The capital plan is funded through a combination of MTA, state and New York City dollars — many of them borrowed.

Haven’t they tried this before?

Yes. The LIRR has considered building a third track for decades. A previous push about 10 years ago was defeated by local opposition, including from homeowners concerned that the LIRR would take their property to build the new track.

So how is this any different?

Gov. Cuomo has promised “unprecedented public outreach” in the new plan, which does not require taking any residential properties, but will require building on some commercial properties. Unlike past proposals, the new effort also includes the elimination of seven grade crossings, which project officials say will reduce traffic accidents, congestion, and noise. Sound-attenuating walls, nearly 2,500 new parking spots, and station improvements are also part of the plan.

How’s a third track going to fit?

It would be built south of the existing tracks from Floral Park to Mineola, and on the north side through Hicksville. In some areas, the existing two tracks would be shifted slightly to make room for the new track. The LIRR says the third track would be built entirely within railroad property.

So what’s the down side?

Opponents in villages near the tracks still have concerns over how prolonged construction will affect their quality of life, including road closures, noise, and the impact on local businesses. They say other LIRR improvements, like modernized switches and additional yards, can accomplish most of the railroad’s same goals.

advertisement | advertise on newsday

How far along is the project?

It’s pretty far along and moving quickly. Since Cuomo proposed the project in early 2016, the LIRR has already completed a draft environmental impact statement, held public hearings, and has begun to look at potential contractors to design and build the project.

What’s next?

The LIRR is holding six public hearings in January to gather input that will go into a final environmental impact statement. The railroad expects to put the project out to bid and award a contract for its design and construction in the coming months. Construction is expected to begin later this year.