The main battle during the years it languished in Congress was how to pay for the new roads. Some thought all the necessary cross-country links could be paid for with tolls, as the Pennsylvania Turnpike had been. Trucking interests were strongly against excise taxes. In 1955, the Eisenhower Administration proposed an "autonomous government corporation" that would sell bonds to pay for the system; Virginia Sen. Harry Byrd decried such an approach as "the end of honest bookkeeping." The breakthrough on financing came from Hale Boggs (D-La.) and George Fallon (D.-Md.) in spring 1956, a rise in the federal fuel and excise taxes that would make the program "pay-as-you-go."

To get the support of urban congressmen, additional urban segments were added to the "Yellow Book" (maps of routes) that would serve central city industrial districts and keep downtown office and retail relevant to increasingly suburban metro areas. Only a few critics like Lewis Mumford worried about the highways possibly doing more harm than good to the cities.

It's not really appropriate to talk about Eisenhower "envisioning" the concept, which FDR and others had previously outlined. As Earl Swift notes in The Big Roads, p. 157: "When Dwight Eisenhower took office in January 1953, the Interstate Highway System had officially existed for more than eight years....He entered the Oval Office professing an interest in building 'a network of modern roads'.... He didn't know that the executive and legislative branches had already worked out the details of the network he sought."

The other major players—Thomas MacDonald of the Bureau of Public Roads, Sen. Albert Gore, Rep. Hale Boggs, even FDR—were as important as Ike or moreso. Modern readers love to elide from Eisenhower's 1919 convoy to his viewing of German autobahnen to the last-minute insertion of "and Defense Highways" into the congressional bill title to the blue signs that went up in 1991, making it a simple "great man" story. In between, of course, were the parkways of New York and Washington and LA, the urban superhighways of Detroit and Chicago, the Pennsylvania Turnpike—and the interminable congressional funding fights of the 1950s.

The Yellow Book showed general routing of the links, but detailed routing was left to state and local officials. So it wasn't until the 1970s that the most contentious urban links were pushed through, and a fair number were cancelled after the "freeway revolt" and growing environmental awareness changed public opinion of superhighway costs and benefits.

Eisenhower (a big-picture guy) later claimed to have been unaware that the program included urban freeways, convening the Bragdon committee in 1959 and claiming that he had never seen a Yellow Book. See J.S. Bragdon, Memorandum for the Record, Nov. 30, 1959 (Bragdon Files, Eisenhower Papers, Eisenhower Library). Online here

I like The Big Roads as the most readable history, but Mark Rose's Interstate: Express Highway Politics 1939-1989 is the more complete scholarly source regarding the Congressional history.

Was the kind of resistance different than a modern road or highway project?

What went into the decision to send interstates directly through cities instead of avoiding them like the Europeans do?

The primary bone of contention was finding formulas (population-based formulas would favor the Northeast, land-based formulas favor the west), and the fact that some governors wanted to keep highway building in state (construction jobs being an easy way to reward political friends).

Essentially, the age old bones of contention in Federal politics: who pays and who gets to lead the decision making.

Source to start: http://www.fhwa.dot.gov/publications/publicroads/96summer/p96su10.cfm

Okay. the development of the highway system had a number of obstacles to overcome. Some of them were internal to President DDE's development team. Eisenhower himself was seeking a "`dramatic' plan to get 50 billion dollars worth of self-liquidating highways under construction," and preferred to avoid increasing the national debt to do it.

Major General JS Bragdon, a West Point buddy of DDE and veteran military engineer, was appointed to Public Works Planning, within the Council of Economic Advisers. A political noob, he proposed a national highway authority that would strip states of their highway agencies and centralize responsibility for planning, financing, and construction in the Executive. Congressmen did not like this idea. State officials weren't pleased either.

As for financing the cost of massive construction, many competing ideas were put forth. An old law started in 1916, allowed for federal-state matching funds; why not continue sharing the cost between a state govermnent and the Federal government? Francis DuPont, the head of the Bureau of Public Roads and past head of the Delaware State Highway Commission, wanted the federal government to foot the whole bill, which would stimulate the economy as well as having longterm social benefits. Meanwhile, Bragdon wanted to pay for the highways with a national system of tolls.

Well, DDE was going to give a speech to all the governors at a special conference, but a relative died and so Nixon had to give the speech. Here is an excerpt:

Now, let us look at the highway net as it should be. The President believes that the requirements are these: a grand plan for a properly articulated system that solves the problems of speedy, safe, transcontinental travel -- intercity communication -- access highways -- and farm-to-market movement --metropolitan area congestion -- bottlenecks -- and parking.

Second, a financing proposal based on self-liquidation of each project, wherever that is possible, through tolls or the assured increase in gas tax revenue, and on Federal help where the national interest demands it.

And third -- and I would emphasize this, particularly at this Conference, because I know how deeply the President believes in this principle: a cooperative alliance between the Federal government and the States so that local government and the most efficient sort of government in the administration of funds, will be the manager of its own area.

And the fourth, very probably, a program initiated by the Federal government, with State cooperation, for the planning and construction of a modern State highway system, with the Federal government functions, for example, being to advance funds or guarantee the obligations of localities or States which undertake to construct new, or modernize existing highways.

Notice that the proposal is for roads that generate their own revenue or taxes levied to fund them, and for state-federal partnership in managing the project.

Having publicly called for a national highway system, DDE needed to get the ball rolling faster than his disunited advisory team was doing. So he appointed 2 more teams, one headed and selected by another Army buddy, Lucius Clay. Clay's Presidential Advisory Commmittee on a National Highway Program was