This was the first proposal which included many more projects (like city buildings) that weren't ultimately contained and included in the $63.5 million bond issue. There are many of the key assumptions that the bond issue is based upon. Remember, this comes from early on in the process and many of the assumptions have been updated - like the 3.14 millage rate.
It is important to review since you can see the results of a systematic evaluation of the conditions of streets and there are more cost breakdowns in this document than I have seen in others. Leave questions as comments below.