About 54 percent ($643 billion) of the law’s $1.2 trillion total goes toward surface transportation, into a massive five-year authorization (through 2026) of federal transportation law that’s nearly twice the size of the FAST Act that it replaces. The rest goes toward other non-surface transportation infrastructure needs. Two-thirds ($432 billion) of that $643 billion is flowing to conventional highway programs. And when compared to the previous five-year law, the new infrastructure bill increases highway program funding by 90 percent, transit funding by 79 percent, and rail infrastructure funding by 750 percent.

As i read it, that says 2/3 of 54% is surface transportation, including rail and bridges etc. so roughly $425B out of 1.2T. So, not mostly highways.