Michael Lewyn

<!--[endif]---->Decades ago, ecologist Garrett Hardin wrote about the &quot;tragedy of the commons&quot;- when an action that is rational for one person becomes irrational when widely practiced.  <p class="MsoNormal"> For example, suppose that there are a few dozen cattle ranchers near a pasture open to all.<span>  </span>It makes sense for each rancher to let as many cattle graze as possible on the pasture, so that the ranchers can feed their cattle without buying additional land.<span>  </span>But if every rancher lets as many cattle as possible graze, sooner or later the land will be overgrazed and the cattle may starve. </p>

<p> In the early 1990s, transportation politics at both the state and federal levels was often fairly simple: an all-powerful Road Gang (made up of real estate developers and road contractors) typically got whatever it wanted, rolling over a much weaker pro-transit coalition of environmentalists and urban politicians. </p>

<p class="MsoNormal"> <span style="font-size: 11pt; font-family: 'Century Schoolbook'">A couple of months ago, I wrote a blog post comparing the safety of inner suburbs and outer suburbs. (See <a href="/node/56468">http://www.planetizen.com/node/56468</a> )</span> </p> <p class="MsoNormal"> <span style="font-size: 11pt; font-family: 'Century Schoolbook'">My post showed that (in least in the metropolitan areas I looked at) inner suburbs were safer than outer suburbs, because violent deaths from murder and traffic combined were lower in the former.</span> </p>

<p> Arguments over transportation policy often run as follows: </p> <p> HIGHWAY SUPPORTER: Highways pay for themselves! Buses/trains don&#39;t! So highways good and everything else bad bad bad! </p> <p> TRANSIT SUPPORTER: But highways create bad externalities like pollution and climate change! So if highways were taxed at their true cost gas would cost a zillion billion cajillion dollars per gallon! (followed by numerous counterarguments and counter-counterarguments that I won&#39;t bore you with, except as written below...) </p> <p> It seems to me that these arguments miss one point: even if the highway system as a whole pays for itself, the system is so chock full of cross-subsidies that each individual road doesn&#39;t (except for toll roads). </p>

<p> I occasionally have speculated that our aging society would lead to increased transit ridership, as seniors lost the ability to drive. But I recently discovered that seniors are actually less likely to use public transit than the general public. One study by the American Public Transit Association showed that 6.7% of transit riders are over 65 (as opposed to 12.4% of all Americans).(1) The oldest Americans are even more underrepresented on America&#39;s buses and trains: only 1.5% of transit riders are over 80, about half their share of the population (2). The only other age group that is underrepresented on public transit is Americans under 18. </p>