I’ve been trying to tease apart some hard numbers on energy and finance these past couple of weeks. I think I finally am getting a handle on them.

The first one that was giving me trouble was energy.  As I’ve written before, the energy usage for electrically powered vehicles is sort of a sham.  The energy that goes into electricity is mostly lost in generation, at least when we use steam to generate electricity via a dynamo.  Even with the economic switch to natural gas over coal, we are still running at about 25% efficiency.  Natural gas does more good for our Carbon budget than solar, by displacing coal in regional power plants, it is still the same old inefficient reaction.

This was pointed up, along with a great many not so nice things, in an antique web page by Randall O’Toole.  At the time of writing, the transit “fact book” was using 1 kWh = 3,000 BTU, when the real energy consumed by generated electricity is closer to 11,000 BTU/kWh.  I had to check and recheck the data and its sources to see that yes, the latest transit energy stats show 11,000 BTU/kWh.

Using that information, I can now happily and confidently report that the average passenger miles per gallon for rail transit is 108.  It is only 28 PMPG for traffic. This is a distinct difference that would not have worked out if I was basing my numbers on 3,000 BTU/kWh. I already found that the fleet efficiency of buses is even worse than for traffic.  I expect they would do themselves the most good by making their routes direct and fast.  Subdivisions, parking lots and malls be damned.  This is still nowhere near as good as 360 PMPG for walking, and 700 PMPG for biking, but its good to know that yes, rail transit is more energy efficient than  traffic.  Cost be damned.

The second quest I’ve been on is the way we pay for it all. I found it was best to surrender the need to parse rail from bus transit, and to split biking from walking facilities, to get some of these numbers.  I also found that separating federal, state and local was not as interesting as the gross revenues and expenditures, and how we make up the difference.

I found the spreadsheet here to be most educational.

Sometimes it takes a hostile author to lay out the ugly truths. I owe it to sites like the Cato institute and Heritage for explaining that the Highway Trust Fund is the source of these omnibus spending bills.  The billions of dollars in earmarks and big vision projects in every congressional district is funded by every driver, 18 cents at a gallon.  Since 1964s Highway bill and 1992’s ISTEA, this has included a boon to transit, biking and walking for better or for worse.  Money diverted from the great driver of wealth in the transportation sector, gas and other transportation related taxes.

But the Gas tax has never paid for all of it.  We have always been diverting funds from the “general fund” (our income tax dollars) to pay for this.  Notably that general fund is currently 40% over budget, at least at the federal level.  Keep buying those US savings bonds, or the highways are done for!

There are two ways to look at this.  If we think of transit, biking and walking as things we don’t have enough of, or as the gas tax in service of transportation( the act getting there on time, wherever and however), devoting gas tax money to these modes makes perfect sense.  Traffic operates better with fewer vehicles on the road after all.  I f people have other ways to obviously make some trips, traffic sees a benefit in less congestion.  This is is a good philosophy for flush times, when there is plenty of cash to go around.

But that’s not the case when times are lean.  When the budget of the gas tax and transportation spending is no budget at all, we haven’t raised it for over two decades, and fuel efficiency has become a virtue, it is little surprise that the gas tax is not the cash cow that it was meant to be.  Now there are schemes about raising the gas tax, or linking it to VMT, or even replacing it with a surcharge on other taxes like the sales tax.

How much could we save if we enabled transportation that was more affordable than traffic or transit?  Walking and biking are an order of magnitude more affordable than these two common modes, but they are almost unseen in the conversation about America’s transportation.  Maybe it is time to let them loose.