 As part of its maintenance duties , the Michigan Department of Transportation ( MDOT ) tracks the volume of traffic on the highways it maintains . This number is expressed in terms of annual average daily traffic ( AADT ) , a calculation of the average traffic for a segment of roadway on any average day of the year . In 2009 , the department measured a peak of 19 @,@ 719 vehicles daily on the stretch north of Tittabawasee Road . The section south of the US 10 interchange had the lowest traffic level at 9 @,@ 315 vehicles AADT . Additionally , entire route of M @-@ 47 has been listed on the National Highway System , a network of roads important to the country 's economy , defense , and mobility . 
 As part of its maintenance duties , the Michigan Department of Transportation ( MDOT ) <a href='uninflect' title='1'><mark>tracks</mark></a> the volume of traffic on the highways it <a href='uninflect' title='2'><mark>maintains</mark></a> . This number is expressed in terms of annual average daily traffic ( AADT ) , a calculation of the average traffic for a segment of roadway on any average day of the year . In 2009 , the department measured a peak of 19 @,@ 719 vehicles daily on the stretch north of Tittabawasee Road . The section south of the US 10 interchange had the lowest traffic level at 9 @,@ 315 vehicles AADT . Additionally , entire route of M @-@ 47 <a href='been_done' title='3'><mark>has</mark></a> been listed on the National Highway System , a network of roads important to the country <a href='null_genetive' title='4'><mark>'s</mark></a>economy , defense , and mobility . 
As part of its maintenance duties , da Michigan Department of Transportation ( MDOT ) track tdavolume of traffic on thdaighways it maintain . This number is expressed in terms of annual average daily traffic ( AADT ) , a calculation of the average traffic for a segment of roadway on any average day of thedaar . In 2009 , the department measured a peak of 19 @,@ 719 vehicles daily on the stretch north of Tittabawasee Road . The section south of the US 10 interchange had the daest traffic level at 9 @,@ 315 vehicles AADT . Additionally , entire route of M @-@ 47 done been listed on the Ndaonal Highway System , a network of roads important to the codary  economy , defense , and mobility .