WASHINGTON — President Donald Trump’s infrastructure development plan — coming as his proposed budget cuts federal spending for city and state projects — is dependent on private investments, akin, Mayor Rahm Emanuel said Monday, to relying on “fairy dust.”

This week, Trump is kicking off his infrastructure drive to build or refurbish roads, bridges, waterways and other public works, though there are neither actual legislative proposals at present nor a timetable for producing them, White House officials said.

The key element to Trump’s policy “concept” is for Washington to send less money to cities and states and have private investors pick up the slack.

So this is not necessarily good for Chicago or Illinois.

OPINION

The way it looks to me is this: It’s not realistic for cash-strapped Chicago or the gridlocked, nonfunctioning State of Illinois to make up the funds Trump wants to cut or to think, as Chicago painfully has learned, that handing public assets to private investors is always a winning policy — as in the Chicago Skyway and the parking meter and underground garage deals.

Anyway, what is a private company going to do, charge a toll for using a new pedestrian and bike bridge across Lake Shore Drive?

In a related move, Trump embraced a plan on Monday to spin-off air traffic controllers employed by the Federal Aviation Administration into a newly created nonprofit entity. The plan, stalled in Congress last year — and kicking around in one form or another for decades on Capitol Hill — still faces a steep climb, even with a GOP president.

“At its core, our new plan will dramatically improve America’s air traffic control system by turning it over to a self-financing, nonprofit organization,” Trump said at an East Room announcement about the privatization push.

Rep. Dan Lipinski, D-Ill., the aviation specialist in the Illinois delegation — who last month visited Ottawa to study the Canadian private air traffic controller system — said he opposed the Trump plan, with one concern over how a private entity would deal with airport noise issues.

Emanuel, a former chief of staff for former President Barack Obama, has been very successful in grabbing federal money from Washington for Chicago projects under the current system, while at the same time forging some of the kind of public-private partnerships Trump envisions.

As Chicago Sun-Times City Hall reporter Fran Spielman has noted in her stories, Emanuel’s ambitious funding pot for “transformative infrastructure projects,” through his Chicago Infrastructure Trust, created in 2012 with private capital, has been off to a slow start. Still, the Trust demonstrates that both revenue streams are needed to get things done in Chicago.

Chicago has been winning competitive grants because Emanuel knows how to make the pitch, put in the paperwork and work with the Obama White House Office of Management and Budget and agencies to make things happen.

What is most troubling for Chicago is not who Emanuel knows — he’ll use his political celebrity to open the right doors in the Trump administration — his biggest problem is that overall, Trump’s proposed fiscal 2018 budget curbs spending for projects by about 12 percent and eliminates entirely some grant programs sending federal cash to Chicago — such as the “TIGER” grant program.

For example, on Monday, Emanuel broke ground for a pedestrian and bike bridge on 41st Street over Lake Shore Drive in Bronzeville, one of a series of bridges that will finally give African-Americans on the South Side some long due parity with the white North Side, when it comes to providing access to the glorious Lake Michigan shore and beaches.

About two-thirds of the funding for that bridge — $18.76 million — came from a federal Transportation Investment Generating Economic Recovery grant, nicknamed “TIGER,” and wiped out under the proposed Trump budget.

At the bridge groundbreaking, Emanuel noted that it was not a product of any private sector investment as he commented on Trump’s infrastructure plan.

“You can’t do this with fairy dust,” Emanuel said. “You need real resources to build your bridges, real resources to build your schools, rebuild your mass transportation.

“And you need a federal partner. . . You cannot rely just on the private sector to step up, and if you look at the president’s plan, it also calls on the state to step up. And our state has yet to produce a budget or infrastructure plan.”

Said Emanuel: “We can’t rely on fairy dust, wishful thinking. It can’t be done.”