After reviewing the above secondary sources and actual indicators of need it is quite apparent that Michigan cannot continue for long without additional investment in the transportation system. Key indicators related to VMT and CVMT growth, pavement condition trends, congestion trends, maintenance of spending levels for the state trunkline system, debt service levels, and local county/city spending levels all strongly suggest the need for sizeable investment in additional road funding.

The amount of need is very difficult to estimate. However, it would appear to be in the vicinity of $1 to $1.5 billion per year assuming the current backlog of state and local road needs can be worked off over a 15 year period.