NCHRP Project 12-33 was initiated in mid-1988 with the objective of developing specifications for bridge design based on the load and resistance factor design philosophy that can be recommended to AASHTO for consideration for adoption. (See Project 12-33 writeup for more detail.) A number of agencies and individuals were employed during the course of the project for various tasks and responsibilities.

The agency employed on Project 12-33C acted under the direction of the Principal Investigator on Project 12-33, Dr. John Kulicki. D'Appolonia was responsible for developing specification provisions relating to soil-structure interaction systems such as culverts, anchored walls, mechanically stabilized earth walls, and prefabricated modular walls.