Senator Eliot Shapleigh - El Paso, Texas

(Ruth Fremson/The New York Times) WANTED: JOBS President Obama promoted his stimulus plan last week in Elkhart, Ind., where the jobless rate is 15.3 percent.

There is no shortage of big dreams or grand schemes as the United States struggles to rebuild itself for the 21st century. But many of the most ambitious projects in the country — a representative sample of which are listed below — stand to get only modest amounts of money, if any, from the economic stimulus package that Congress approved on Friday.

From a public works perspective, the $789 billion stimulus package is unlikely to transform the physical fabric of the nation as the New Deal did when it built hundreds of airports, tens of thousands of bridges, and hundreds of thousands of buildings and miles of roads.

The final plan devotes more than $100 billion to public works projects — but that is only a fraction of the $2.2 trillion that the American Society of Civil Engineers says is needed to put the nation’s infrastructure into a state of good repair. And much of it is likely to be spent on small needs sprinkled throughout the 50 states — repaving a road here, painting a bridge there — rather than on bigger, more transformative, but slower projects. To put the scope of the spending into perspective, think of it this way: the bill will devote about $50 billion to transportation projects, which is about what the federal government authorizes for transportation every year. The money will be welcome, but hardly enough to transform transportation. And since many local governments have curtailed their own construction programs to save money, in some places the stimulus may end up simply keeping public works at their pre-recession pace.

Advocates say they are worried that the plan represents a missed opportunity. “The equation shouldn’t be do we do short-term investment or do we do long-term investment, because we need both,” said Felix Rohatyn, the financier whose new book, “Bold Endeavors: How Our Government Built America, and Why It Must Rebuild Now” (Simon & Schuster, 2009), uses examples like the building of the Erie Canal, the transcontinental railroad and the Interstate System to argue that the nation needs to build for the future with more ambitious, better-planned projects today. “Infrastructure is an investment, not an expense.”

Californians want finally to bring high-speed rail to the United States. Planners want to build bridges to Canada from Detroit, a tunnel for trucks to the Port of Miami and a new one for trains between New York and New Jersey. Transit systems want to expand, ports want more capacity and freight train companies want to untangle bottlenecks on the tracks.

But even with the biggest push for infrastructure spending in years, most of these big-ticket projects are unlikely to get very far from the stimulus alone. Some may not qualify for aid at all. Others will get modest down payments, which they hope will be enough to keep them going. A few may see enough federal money to become reality. Here is a look at 11 ambitious infrastructure projects around the country — some of which have been in the planning stages for decades, and others of which have been identified recently as pressing needs by officials in their regions.

California High-Speed Rail: $45 billion

High-speed trains are increasingly common in Asia and Europe, but they have yet to make it to the United States. Now Californians are trying to change that. In November, California’s voters approved a measure authorizing $10 billion in borrowing to begin work on an 800-mile high-speed train capable of going more than twice as fast as the average speed of the Acela trains on the East Coast, and which could make the trip from San Francisco to Los Angeles in 2 hours and 40 minutes. Supporters say that the plan would reduce congestion on highways and at airports and invigorate the economy; skeptics question whether the plan makes economic sense. The final bill includes $8 billion for high-speed rail; but there are 11 regions that could compete for the money, which would at most be a small down payment on what promises to be a costly project.

NextGen Air Traffic Control: $15 billionto $22 billion

With long flight delays increasingly common, many aviation experts argue that a complete overhaul of the air traffic control system is needed. For more than a decade the Federal Aviation Administration has talked about what it calls NextGen — a plan to move from the current radar-based system to satellite navigation, in which airplanes would use G.P.S.-like technology to find their positions and broadcast that information to other planes and to controllers on the ground. Backers say that the new technology would relieve congestion delays by allowing planes to fly closer together and to chart more direct flight paths. But the plan would require substantial investment not only by the government, but by the airlines as well.

California Drinking Water: Tens of billions of dollars

Officials say that a major source of drinking water for about 25 million Californians is at risk. That water currently comes from the delta where the Sacramento and San Joaquin Rivers meet, and the levees that protect the region are more than 100 years old and are vulnerable to earthquakes. A state task force recommended restoring the delta’s endangered habitat and building a new aqueduct to bring water from Northern California to the arid south, without passing through the delta. A similar proposal was voted down in 1982 because northerners viewed it as a water grab by the south, and farmers in the delta region feared losing their water. But the current drought, and climate change, have provided a new sense of urgency. The bill included $50 million that can be used in the delta region, but that is only a tiny fraction of what the state estimates it will eventually need.

Gulf Ports: $1.04 billion for New Orleans; $1 billion for Gulfport, Miss.

Several ports on the Gulf of Mexico have begun ambitious expansion plans, which they say will put them in contention to handle more cargo from Asia after the Panama Canal finishes a widening project that will allow bigger ships through. The Port of New Orleans has a billion-dollar expansion to help anchor the economy of a region still battered by Hurricane Katrina. And the port in Gulfport, Miss., has its own billion-dollar plan to rebuild itself above sea level. It plans to pay for part of it with money from the Department of Housing and Urban Development, to the dismay of local housing advocates. Proponents say that both plans could save and add jobs in the hurricane-ravaged region, but there have been indications that less cargo is coming in because of the economic downturn, and they would still have to compete with the West Coast ports, which get most of the cargo from Asia, and, closer to home, Houston’s bustling port.

Seattle Highway Tunnel: $4.24 billion, to be paid by the state, the city and the county

The elevated highway that runs along Seattle’s waterfront, the Alaskan Way Viaduct, is considered near the end of its useful life. It has been worn down by more traffic than was anticipated when it opened in 1953, damaged by a past earthquake, and deemed vulnerable should another one hit. Last month, state and local officials in Washington announced that they want to tear it down and replace it with a 1.7-mile tunnel, while strengthening the sea wall and expanding transit in the area. Supporters say the project, which still needs legislative and environmental approval, will make drivers safer while easing access to the city’s waterfront. Skeptics warn about the delays and huge cost overruns Boston faced when it sank its highway in the Big Dig.

Hudson Rail Tunnel: $8.75 billion

At rush hour, the railway tunnels under the Hudson River between Manhattan and New Jersey operate at peak capacity, so there is no way to run more trains back and forth even though the demand is great. The Port Authority of New York and New Jersey and New Jersey Transit have been planning to build a second tunnel, which they estimate could take 22,000 automobiles off the streets at rush hour. The project has federal approval, and is mostly locally financed. An infusion of federal money could get the project well on its way to reality.

Chicago Rail Network: $2.5 billion

A quarter of the nation’s rail freight rolls through Chicago, but the rail network there has become so snarled that it can sometimes take longer for freight trains to make it through Chicago than to reach Chicago from the West Coast in the first place — slowing the movement of goods across the country and adding to their cost. For years there have been plans to untangle the system, but they have faced problems getting financing. Now some projects are getting started, but there is a long way to go.

Miami Port Tunnel: $1 billion

Trucks cannot reach the bustling Port of Miami, which is on an island, without rattling through downtown Miami. Local officials and developers in downtown Miami want to build a tunnel to the port to relieve that truck congestion. But the project, which was to be built through a public-private partnership, was dealt a serious setback late last year when the state announced that its private partners were having trouble raising money. Local officials would like to see federal aid for the project.

Second Avenue Subway: $4.35 billion

New York is moving ahead with its long-delayed plans to build its first new subway line in generations, restarting a project that was last halted during the 1970s fiscal crisis, leaving unused, unfinished tunnels beneath city streets. Work is going on now, but the question is whether the project can weather yet another fiscal crisis. The Metropolitan Transportation Authority is under considerable financial stress and is looking for sources of money to keep its ambitious capital program going forward.

Bridge to Canada: $1.8 billion (U.S. share)

It is one of the nation’s busiest border crossings, but Detroit is linked to Canada only by a tunnel and an 80-year-old privately owned bridge. The United States and Canada are working together to build what they are calling the Detroit River International Crossing, a new six-lane bridge, and last month they got the final environmental clearance from the federal government. (They still need some local government approvals to acquire some land.) But the owner of the current bridge, the Ambassador Bridge, is moving ahead with a plan to build a new, privately owned bridge to replace the one he owns. With border crossings down these days, it is unclear if the Detroit River needs two new bridges, though state officials say it does. And officials say the severely depressed local economy could use the 10,000 jobs they say the public bridge project would generate on the Michigan side of the border.

Dulles Airport Train: $5.2 billion

Sometimes arriving at Dulles International Airport can feel like only half the journey to the nation’s capital: what follows is a 25-mile, $58 cab ride. But last month the federal Department of Transportation gave its approval to a plan to extend Washington’s Metrorail through northern Virginia to the airport by 2015. The first phase of the project already depends on the federal government for $900 million.