Another week brings another measure of just how bad Atlanta traffic has become.

A study released today shows nearly 4 percent of metro Atlanta commuters travel 90 or more minutes to work each day. That’s ninth-worst among the country’s large metropolitan areas, according to the Apartment List analysis of U.S. Census data.

Nationwide, about four million workers – or about 2.8 percent of commuters – travel an hour and a half or more to work, the study found (you can read it here).

Apartment List, a web site that lists, well, apartments for rent, says the rise of these “super commuters” can be attributed to rising housing prices in expensive cities and inner suburbs and a lack of investment in public transportation. In fact, super commuters are more likely to rely on public transportation than those with shorter commutes, the study found.

The share of super commuter is highest in expensive metro areas with strong economies like San Francisco, Los Angeles and New York, the study found. The city with the most super commuters? Stockton, Calif, where 10 percent of commuters traveled 90 minutes or more to work (often in the San Francisco area).