As part of our State of Metropolitan America project, we reported last week on the increase in public transit commuters from 2000–2008. While this increase is small (less than 1 percent), it’s the first time that’s happened in 40 years. As the map below shows, most transit commuters are concentrated on the coasts.

But what type of transit saw upticks? One would assume that light rail or commuter rail would be responsible for the increases since system mileage increased by 67 and 40 percent, respectively, over the period. Nope. In the 100 largest metro areas, only about 12 percent of the increase (about 163,000 workers) came from light rail and commuter rail. About half a million more commuters report that they get to work mostly by subway or “heavy” rail but, still, this only explains 36 percent of the increase.

By far, bus riders made up the largest share of the increase in transit commuters from 2000 to 2008—about 700,000 more people. And these are pretty much the large places you’d expect: New York, Los Angeles, Washington, Chicago, and Seattle alone are responsible for half of those new bus riders.

Which metros saw declines in bus riders? Well, outside of New Orleans, the biggest drop was in the Dallas Metroplex which actually increased its overall number of public transit users thanks to continued investment in that region’s light and commuter rail systems. We don’t know from the data if workers were giving up the bus for the rails but look for future Avenue posts on the demographic makeup of American commuters.

In the meantime, the latest data for all bus riders (not just commuters, which the Census reports) shows that the number of bus trips are down nearly 4 percent from the first quarter of 2009 to the first quarter of 2010. Strikingly, the declines are mostly being felt in the largest systems. Those in metros with over 2 million people saw the largest drops (down 5 percent). In fact, of the largest systems, only Minneapolis’ Metro Transit saw any increase (0.2 percent). It does look like the recession and certain service cuts are having a major impact on these bus numbers.