I've got a bridge to sell. It's made from watered-down concrete and comes with blueprints written on site. It was very important to get the implementation started asap to shorten the review cycle.
In a way, bridges are kind of agile. There are many stages of things like site selection, geological testing, architectural and engineering design decisions, computer simulations, traffic forecasting, etc. All of that happens in a feedback loop with the customer (eg some state DOT).