Julie -- thanks for asking; I must admit I am not that knowledgeable re: pavement. I think to research your question, I would need access to membership-only engineering web sites. However, I would take an educated guess that our combination of groundwater and geology is fairly unique for a large city; add a wet, freezing weather to the mix and we should change our name to Pothole City.
I have only lived in Spokane and Seattle, altho I have travelled along the West Coast. Spokane has much more severe winters but is much drier, so it doesn't have an extensive problem with potholes (I left there in 1978, so who knows now ...)
I have never been to another city where water seeps up through the pavement like it does here, even on a dry day after a dry stretch. The best nearby examples are Beach Drive where the landslides have been and Morgan St/Sylvan Way between 35th and Delridge (you can actually see the long-term effect of the water draining diagonally across the roadway.) There is a cistern in front of my condo on California a few blocks south of Morgan St and you can hear water running in it 24/7, 365 days a year.
Frankly, the Europeans take a long-term view of these things; American culture is as yet not willing to invest in the future.
Here are some good explanations of how Seattle's water problems impact our roads:
http://www.seattle.gov/transportation/potholes/
http://www.kingcounty.gov/transportation/kcdot/Roads/RoadsMaintenance/RoadRepair/PotholeRepair.aspx