Primary go-to resource containing comprehensive resource information on Transportation Asset Management (TAM) is the TAM Portal found at the AASHTO Transportation Management Hub : https://www.transportationmanagement.us
Here are some of the key links pertaining to Transportation Asset Management:
FHWA Websites:
Asset Management http://www.fhwa.dot.gov/asset/
Transportation Performance Management https://www.fhwa.dot.gov/tpm/
Planning, Environment, and Realty http://www.fhwa.dot.gov/hep/
FTA State of Good Repair and Asset Management http://www.transit.dot.gov/TAM
AASHTO TAMP Builder http://www.tamptemplate.org/
ISO Standards for Asset Management http://www.iso.org/iso/news.htm?refid=Ref1813
Current Research Needs Statements https://www.mytrb.org/RNS/Search