Traffic, structural model, materials, environment. I found a few websites that seem to have repackaged this professor's lecture notes and then found the origin

Traffic, structural model, materials, environment. I found a few websites that seem to have repackaged this professor's lecture notes and then found the original.[1] The most unexpected insight was that slow traffic is a big factor. NY and LA definitely have slow traffic compared to most other cities in the US. [1]: Mathew, Tom V. "Factors affecting pavement design." 3 August 2009. https://www.civil.iitb.ac.in/tvm/1100_LnTse/402_lnTse/plain/plain.html https://www.civil.iitb.ac.in/tvm/1100_LnTse/402_lnTse/plain/... " I also found this Virginia Tech paper that lists a number of citations that may provide additional insight, https://vtechworks.lib.vt.edu/handle/10919/56449 https://vtechworks.lib.vt.edu/handle/10919/56449