If that was really true we wouldn't have an Interstate Highway system and the WPA wouldn't have built us out of the recession. Oh, and we wouldn't have bridges and airports and, um the Internet.
At the moment there are highways that are crumbling all over the country. Fixing them would good for public safety, create jobs and stimulate the economy.
Also, our rail system sucks at the moment compared to western europe or Japan and causes people to fly or drive a lot of places when it would be much better for the environment if reliable train service was available. Building more train tracks and adding more train routes would create jobs, be good for the environment, and have a host of lasting benefits for years to come.
The list goes on and on.