SAN FRANCISCO (MarketWatch) -- President Barack Obama unveiled Monday a $50 billion plan to upgrade the nation's roads, airports and railways, choosing a Labor Day rally in Milwaukee to announce the administration's latest proposal to revive the economy.

The proposal includes an overhaul of the nation's highways, bus and rail systems, and air-traffic controls.

"All of this will not only create jobs now, but will make our economy run better over the long haul," Obama said to an audience of mostly labor-union members and their families gathered at a fairground to celebrate Labor Day.

"This is a plan that will be fully paid for and will not add to the deficit over time -- we're going to work with Congress to see to that," the president added.

The public-works plan is part of a larger effort to provide more jobs and help the economic recovery. That larger plan, to be announced Wednesday in Cleveland, would build upon projects and investments already underway through the Recovery Act, White House officials said.

Amid other signs the economy is sputtering, the latest unemployment figures released Friday showed unemployment at 9.6% in August, from 9.5% in July. Read the latest about unemployment figures.

The plan calls for investments over six years. Part of the money would fund an infrastructure bank to invest in projects critical to the economy, while also providing jobs.

The bank would unite private, state and local capital "to invest in projects that are most critical to our economic progress," a departure from "the federal government's traditional way of spending ... through earmarks and formula-based grants" allocated more through geography and politics than value, a White House statement about the plan said.

"Instead, the Bank will base its investment decisions on clear analytical measures of performance, competing projects against each other to determine which will produce the greatest return for American taxpayers," it said. It would focus on "the smartest investments," Obama told the Milwaukee audience.

The plan calls for rebuilding 150,000 miles of roads, building or maintaining 4,000 miles of railways, and constructing or refurbishing some 150 miles of airport runways along with a new air navigation system to cut travel times and airport delays.

As part of the longer-term plan, the government also said it aims to integrate high-speed rail "on an equal footing into the surface transportation program," to ensure a commitment to high-speed rail system; and to streamline and prioritize transportation investments through consolidation of different programs now in place.

It is unclear how many jobs the public-works plan would create. According to news reports, White House officials declined to estimate the total cost of the plan, saying only the initial $50 billion would be a substantial portion of it. It was also unclear whether the plan would get support from Republicans.

Labor Secretary Hilda Solis said in an appearance on NBC's Today Show on Monday the infrastructure plan "will put people back to work immediately" and garner bipartisan support.