The Long Island Rail Road will consider impacts on station parking, air quality and emergency service response time as it goes forward with a plan to build a third track between Floral Park and Hicksville, according to a new report.

The LIRR last week issued its final scoping document for the proposal to construct a 9.8-mile track along the Main Line — giving the railroad more capacity to serve its growing ridership and work around service disruptions. The document, which incorporates the feedback from 750 public comments made in May and June, is meant to guide the railroad in its ongoing environmental impact study, set to be released later this year. Project officials have said construction could begin as early as 2017 and last three to four years.

Although largely the same as a preliminary scoping document released in May, the final report makes new promises about what will be studied in the environmental review: the impacts on parking at some key stations from the increased ridership expected from a service expansion, including at the already over-capacity Hicksville station; potential air quality impacts from diesel trains and from fewer cars on roads; and the impact on emergency response times, especially in communities where grade crossings will be temporarily closed for construction.

Responding to calls from local officials to make other infrastructure upgrades before building a third track, the project team also said it will consider switch and signal upgrades among other viable alternatives to the project.

In a statement issued with the new report, the project team said the plan is “a brand new initiative that’s totally different from previous attempts to add capacity to the busy Main Line,” including a prior third track proposal abandoned about a decade ago amid local opposition. Unlike that one, the new project, proposed by Gov. Andrew M. Cuomo in January, does not require taking residential properties.

“The third track will have an undeniably positive impact on our regional economy that will be felt from our largest companies to our small-business owners,” said Kevin Law, co-chairman of Right Track for Long Island Coalition, a consortium of businesses and other groups supporting the project. “Today we are reassured that those benefits will not be balanced on the backs of a few homeowners — and that this plan has found a way to benefit every single Long Islander.”

advertisement | advertise on newsday

The project team released other new tidbits of information about the project. A new aerial map shows the boundaries of the LIRR’s right of way along the project corridor. Artists’ renderings show how retaining walls could be installed near residential properties to support the new track. Another map details all the “sensitive land uses” along the project path, including Floral Park’s village pool and recreation center, which would be next to the tracks.

Despite assurances that the environmental study will provide even more answers, Floral Park Mayor Thomas Tweedy said he remains disappointed with “the lack of information,” including how much the project will cost and how the state will pay for it. The new report does not provide a price tag, but project officials have estimated it at between $1 billion and $1.5 billion.

“Can you honestly believe that you would do an expansion of your house ... without having a budget?” said Tweedy, who has raised concerns about the project’s impact on village residents. “Believe me, I’m not against development. But development that’s responsible is important.”