I have written many times about my problems with Phoenix light rail -- examples are here and here. We paid $1.4 billion in initial capital costs, plus tens of millions a year in operating losses that must be subsidized by taxpayers, for a line that carries a tiny tiny percentage of Phoenix commuters. Capital costs equate to something like $75,000 per daily round trip rider -- If we had simply bought every daily rider a Prius, we would have save a billion dollars.
But, as with most things the government does, it is worse than I thought. Over the last several years, I have been treating these daily light rail riders as if they are incremental users of the area's transit system. In fact, they are not, by Valley Metro's (our regional transit authority) own numbers. Here is the key chart, from their web site.
Compare 2009 to 2012. Between those years, light rail ridership increased by just a hair under 8 million. In the same time period, bus ridership fell by just a hair over 8 million. So all new light rail ridership is just cannibalizing buses. We have spent $1.4 billion dollars to shift people to a far more expensive transit platform, which does not offer any faster service along its route (the light rail has to fight through traffic lights on the surface streets same as buses).
This is a pattern seen in most cities that adopt light rail. Over time, total ridership is flat or falls despite rising rail ridership, because rail is so expensive that it's operation forces transit authorities to cut back on bus service to balance their budgets. Since the cost per rider is so much higher for light rail than buses, a dollar shifted from buses to light rail results in a net reduction in ridership.
Postscript: Looking at the chart, light rail has achieved something that Valley Metro has not seen in decades -- a three year period with a decline in total ridership. Sure, I know there was a recession, but going into the recession the Valley Metro folks were arguing that a poor economy and rising gas prices should boost their ridership.