The NYS DEC has required the use of retrofit technologies for various state agency, state public authority, and regional public authority heavy duty vehicles, as well as heavy duty vehicles used on behalf of such agencies and authorities. This report was compiled to assist NYS DOT in its efforts to comply in the most cost effective manner possible, without compromising its core functions. The results of the literature review and key points from conversations with fleet managers and retrofit/engine manufacturers form the basis of the quantitative analysis of benefits and costs calculated for various retrofit technologies. These benefits and costs naturally depend on many aspects of the vehicle in question, such as its size, model year, and usage pattern. In the long term, the most cost effective way to reduce PM emissions is to replace the oldest trucks. Another decently cost effective option is to install level 1 retrofits on relatively new class 8 dump trucks, starting with the newest which are compatible. While the long term cost effectiveness should be a key factor in developing emission reduction strategies, there are several other important factors to consider: near-term budget constraint; other possible options; and vehicle and duty cycle compatibility.