In 2005 registration fee and fuel tax revenue, the two primary sources of funds, totaled $1,932.1 million. However, the proportion of funding provided by registration fees has increased significantly since the early 1980s because of the fixed nature of the fuel taxes per gallon and the fact that registration fees are tied to prices of vehicles and therefore inflation indexed. Currently fuel taxes account for 52 percent of funding, but by 2017 this is expected to drop to just 47 percent of the total as registration fees continue to increase.
Overall, to put this data into perspective, registration fees and gasoline taxes cost the average Michigan resident approximately $31.87 per month in 2005, or about 2.4 cents per mile.[29] It is interesting to compare the cost of road access to the costs of other utility-like services. Typical Michigan costs for other utilities are approximately $70 for monthly household electricity service, $50 for cable television service and $60 for cellular service.