There is no law of the universe that says a multiplier must be greater than 1.0. It is entirely possible, and indeed, easy to build a piece of infrastructure that will never pay back.
That's not how the math works with infrastructure projects.
With infrastructure projects there is the upfront cost and immediate returns, but there are also all other externalities and savings from shift in consumer demand and, for example, urban renewal and requalification.
For instance, how much would you save if you cut on the number of cars entering a urban center? This means less pollution, less traffic, less commutting times, etc etc etc
Does that have no value?
Just because there’s no law of the universe that prevents you from throwing money down the drain, doesn’t mean you ought to do so.