Minnesota Department of Transportation

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State Aid for Local Transportation

Vehicle Classification for County Road Pavement Design

semi truck driving down scenic roadway

Vehicle Classification for County Road Pavement Design

The State Aid Equivalent Single Axel Load calculator consists of a two tab Microsoft Excel spreadsheet. The first tab is for use with the recently updated heavy commercial traffic default values. The second tab is for use with site specific heavy commercial traffic percentages. Any spreadsheet cell that is “yellow” requires the user to input a reasonable value. Please have your Excel security setting set to low or click on enable macros for the program to run.

Below are updated percentage default values for the heavy commercial traffic using CSAH. The updated vehicle classification data contains 8 default values. These default values are based upon whether the road is rural or urban and the projected Annual Average Daily Traffic range. State Aid encourages counties to perform actual traffic counts whenever possible for the design of their pavements.

Rural/Urban CSAH Heavy Commerical Percentages

Rural AADT Range
CAR
2ASU
3+ASU
3ASEMI
4ASEMI
5+ASEMI
TT/BUS
TWINS
Total
Average HC PCT
Range HC PCT
1 - 300
86.72%
4.71%
2.24%
0.35%
0.71%
3.81%
1.45%
0.01%
100.00%
13.3%
9 - 38%
301 - 750
86.56%
3.44%
2.17%
0.39%
0.69%
5.32%
1.40%
0.03%
100.00%
13.4%
4.7 - 34.3%
751 - 1500
90.55%
3.69%
1.71%
0.33%
0.57%
2.10%
1.03%
0.02%
100.00%
9.5%
2.2 - 29.0%
1500>
91.39%
2.32%
1.24%
0.16%
0.32%
3.33%
1.23%
0.01%
100.00%
8.6%
2.1 - 19.1%
Urban AADT Range
CAR
2ASU
3+ASU
3ASEMI
4ASEMI
5+ASEMI
TT/BUS
TWINS
Total
Average HC PCT
Range HC PCT
1 - 300
95.60%
1.60%
0.40%
0.40%
0.40%
0.40%
1.20%
0.00%
100.00%
4.4%
*N/A
301 - 750
92.53%
3.70%
1.62%
0.14%
0.24%
1.23%
0.48%
0.07%
100.00%
7.5%
4.0 - 11.0%
751 - 1500
94.72%
2.14%
0.98%
0.19%
0.30%
0.94%
0.71%
0.02%
100.00%
5.3%
1.1 - 10.6%
1500>
96.44%
1.52%
0.46%
0.09%
0.12%
0.89%
0.47%
0.02%
100.00%
3.6%
0.6 - 3.7%

Note: Data from 2007 and 2008 County State Aid Study (Minnesota State University) and 1986 to 2002 vehicle class data (MnDOT). Urban is defined as the area within the boundaries of a city 5000 or more population and the Twin Cities metropolitan area.

*Data based on only one count, so there is no range.

For questions and information, please contact Joel Ulring at joel.ulring@state.mn.us or 651-366-3831.

MnDOT Vehicle Classification Scheme

mndot vehicle classification scheme