Here’s a chart from the Minnesota House Research primer on the state’s County State Aid Highway (CSAH) system (which I referenced in last week’s post on the transportation planning debate).

It’s a bit complicated. For example, according to the House Research document,

For 2013, the excess sum is $133.9 million or around 28 percent of the formula based direct aid provided to counties (that is, excluding deductions). The portion of direct aid distributed via the excess sum formula has been increasing since it was introduced. (Note that the 2012 excess sum amount contains additional funds to correct a 2011 allocation that was too low.)

If you understand that, seek help!

The key point is that the state funds a whole bunch of road construction (and maintenance) through the CSAH formula. The pie chart shows how the money is divided up based on a few different criteria: total milage in the county, equal between counties, per capita car registrations int he county, and total capacity needs [which seems vague to me]. The chart on the right shows the total spending over the last few years.