Based on work done by energy economists over several decades, there are few infrastructure investments that will extend as deep into the economy as new investment in public transport. The solution you’re looking for creates a ton of jobs on the front end, and captures broad based wealth and efficiencies on the back end. An extension to existing railways and new rail lines is the investment that keeps giving, over time.
The schedule of greatest impact is as follows. First, new commuter rail and enhancement of existing commuter rail. Second, new light rail. Finally, high speed rail. In that order.
Let’s consider the front end: steel and copper for the tracks and grid. Lots of manual labor to clear and build the lines, managerial labor to contract the providers, and engineering and manufacturing labor to design and build the trains. Now let’s consider the back end: massive efficiencies in time, in productivity, and fewer cars on the road. Less dependence on oil, and less cost for upkeep of roads. Implications for air quality are obvious. The aggregate savings to society would expand outward for decades.
You should also consider attacking the rail and transport problem using emergency powers. There is not enough time to spend years on the public hearing processes that normally attend these projects. You may also want to first target metropolitan areas where the greatest impact can be made. Los Angeles, Seattle, and Miami are cities that come to mind as rich with enormous, potential savings.
You will not capture many of these long-terms payoffs from investing in bridges and roads, however. While bridge and road projects will certainly be a part of your spending bill, and while they do create alot of jobs upfront, investing in automobile architecture is a poor investment. The back end benefits diminish over time.
Finally, the expansion of public transport, all of it electrified, will drive the need for a better power grid. And in states like California a large increase in public transport can be paired with increases in utility grade solar power generation.
-Gregor