transit the only cost-effective choice to solve nation's transportation problems

Today's C-J story on this 2009 Urban Mobility Report deals with one problem out of many in our our transportation system: congestion delays. Congestion is costly, and the study can tell you all about that. But is congestion cost actually significant in the grand scheme of our household transportation budgets? You'll be surprised. How would you rank these three car driving expenses: gasoline, crash costs, and congestion costs? Read on...

Here's what I came up with - see the Bibliography for the math:

1. Crash costs - 16.6 cents per mile
2. Gasoline costs - 10.4 cents per mile
3. Congestion costs - 2.9 cents per mile

Congestion costs are chump change!

What is Un-be-lieveable is that you actually end up paying more for crash costs than you do for gasoline, right? It took me a while to understand as well - it is like a bizarro-lottery - each year 35-40,000 unlucky winners get death, many more get horribly injured, and the costs for these incidents is like losing the lottery - millions of dollars evaporates for those people and their families. When you average this out, it comes out to more than the cost of gasoline.

The study's thesis is that congestion is costly, and that to combat congestion we need more roads and more transit. But if you look at the overall costs of our transportation system, including the incredibly high crash costs of motoring, you see that more roads are actually a stupid way to "save" money: if you build it, they will come kill themselves.

Roads can be a few percent safer through better engineering, education, and enforcement, but that's about it. Ultimately driving is never going to be as safe - and therefore as cheap - as transit!

For further fun, you can look at how to extend this to other costs of driving. Depreciation on automobiles is a major cost. What about the Iraq war, which many people now acknowledge was a war for oil? If you feel like sharing, go to town in the comments.

Bibliography:

For all calculations, I'm starting with 3e12 vmt, 3 trillion vehicle miles travelled per year, which is the case for both 2006 and 2007 according to FHWA's Traffic Volume Trends for those years.

The annual crash cost comes from On a Crash Course - The Dangers and Health Costs of Deficient Roadways, a recently released study that on page 13 puts US traffic crash comprehensive costs at $4.988e11 - $498.8 billion. From there, just divide that by the 3e12 miles.

The per-mile congestion cost is similar, it just uses the Urban Mobility Report's costs for congestion $87.2 billion.

And the gasoline cost is just a straightforward division: $2.60/gallon over 25mpg. The price was from lousvillegasprices.com.

Citation needed that for the fact that transit is safer than motoring....not gonna be hard, but I'd like to know how much safer.

I gave all this to the C-J, but sadly somehow my quote got stripped of the numeric supporting evidence. Sigh.