It is not common but happens sometimes, even in big infra projects.

One example is Wilson Bridge. http://www.washingtonpost.com/blogs/dr-gridlock/wp/2015/03/3...

Also, near where I live, the new highway between Helsinki and Lahti was built under budget and exceeding schedule. (No links in English unfortunately.)

So it does happen.

The one that always comes to mind is the Empire State Building. It was built in 410 days, 12 days ahead of schedule and right on budget. I guess the design drawings were produced in two weeks, which is staggering to think about.

I'm pretty sure the race for the tallest building at the time probably had something to do with the rate at which they it got it built. They were competing at the time with the Chrysler building for bragging rights as the tallest building and both wanted to get done first.