 = M @-@ 81 ( Michigan highway ) = 
 
 M @-@ 81 is a state trunkline highway in the Lower Peninsula of the US state of Michigan . The trunkline travels from the city of Saginaw at the junction with M @-@ 13 to the junction with M @-@ 53 east of Cass City over the county line in Greenleaf Township in northwestern Sanilac County in The Thumb area of the state . Outside of the cities and villages along its route , M @-@ 81 passes through mostly rural farm country . Near Saginaw it intersects the freeway that carries both Interstate 75 ( I @-@ 75 ) and US Highway 23 ( US 23 ) in an industrial area . 
 A road bearing the M @-@ 81 designation has existed since at least July 1 , 1919 , when the state initially numbered its trunkline highways . Since that time , it has been extended , rerouted or shortened several times . These changes resulted in essentially the modern highway routing by 1926 ; the highway was fully paved in the 1940s . A change made in 1929 was reversed in 1933 , and an extension through downtown Saginaw in the 1960s was overturned in the 1970s . The last change was the construction of a pair of roundabouts at the I @-@ 75 / US 23 interchange in 2006 . 
 
 = = Route description = = 
 
 M @-@ 81 starts at a junction with M @-@ 13 , with the two directions of each highway separated by a median . This central feature ends for M @-@ 81 immediately east of the intersection as the highway runs east out of Saginaw . The trunkline follows Washington Road easterly through residential subdivisions to an interchange with I @-@ 75 / US 23 in an industrial area of Buena Vista Township . This interchange , exit 151 along the freeway , is built with roundabouts on either side of the bridge that carries Washington Road over the freeway in a variant of the diamond interchange design called a dumbbell interchange . After leaving the industrial properties on the east side of I @-@ 75 / US 23 , M @-@ 81 follows Washington Road through a mixture of farm fields and residential subdivisions . North of the community of Arthur , the highway intersects M @-@ 15 ( Vassar Road ) . Further east , M @-@ 81 crosses out of Saginaw County ; across the border in Tuscola County , the highway follows Saginaw Road . 
 In the village of Reese , M @-@ 81 crosses the Huron and Eastern Railway twice . East of town , the highway follows Caro Road through more farm fields through the community of Watrousville . Near the south side of the Tuscola Area Airport , M @-@ 81 turns to the northeast running along the Cass River to Caro . In the city , the trunkline follows State Street past the fairgrounds . At the intersection with Ellington Street , M @-@ 81 crosses M @-@ 24 . The highway continues northeasterly out of town and through the community of Ellington . Northeast of Elmwood , M @-@ 81 turns due east along Cass City Road . The trunkline runs to the village of Cass City where it follows Main Street through residential neighborhoods and the central business district . East of Cass City , the highway crosses the Cass River before crossing the county line into Sanilac County . Approximately one mile ( 1 @.@ 6 km ) into the county , M @-@ 81 ends at the intersection with M @-@ 53 ( Van Dyke Road ) . 
 M @-@ 81 is maintained by the Michigan Department of Transportation ( MDOT ) like other state highways in Michigan . As a part of these maintenance responsibilities , the department tracks the volume of traffic that uses the roadways under its jurisdiction . These volumes are expressed using a metric called annual average daily traffic , which is a statistical calculation of the average daily number of vehicles on a segment of roadway . MDOT 's surveys in 2010 showed that the highest traffic levels along M @-@ 81 were the 17 @,@ 839 vehicles daily between Van Gelsen Road and Frank Street in Caro ; the lowest counts were the 3 @,@ 527 vehicles per day east of Cass City to the M @-@ 53 intersection . No sections of M @-@ 81 have been listed on the National Highway System , a network of roads important to the country 's economy , defense , and mobility . 
 
 = = History = = 
 
 When originally signed around July 1 , 1919 , M @-@ 81 ran from Bay City southeast and east to the Munger area ; from there it ran south concurrently with M @-@ 31 to the Reese area before running northeasterly to the east of Cass City to M @-@ 53 . By 1921 , the eastern end was extended southerly from Caro to Mayville along a highway that is now part of M @-@ 24 . In late 1926 , the western end was changed so that M @-@ 81 followed the former M @-@ 31 from Reese into Saginaw and the eastern end was rerouted from Caro northeasterly to the Cass City area . With the exception of the routing through downtown Saginaw , the highway followed the approximate routing of the current highway . 
 In the latter half of 1929 , the highway was rerouted between Saginaw and Reese , using a set of parallel roadways to the south of the previous routing ; this change was reversed in 1933 . M @-@ 81 was fully paved when the last section between Ellington and Elmwood in Tuscola County was finished in late 1946 or early 1947 . 
 Starting in 1953 , the westernmost approximately one mile ( 1 @.@ 6 km ) of M @-@ 81 was also used for a US 23 concurrency . When the bypass of Saginaw was completed in late 1961 , M @-@ 81 was extended along M @-@ 13 southwesterly into downtown Saginaw where it turned west across the Saginaw River to Midland Road west of the city . This routing across the city was removed in 1971 when I @-@ 675 was completed ; west of that freeway the highway became M @-@ 58 , the rest was either removed from the highway system and turned back to local control , or it had the M @-@ 81 designation removed . Since this truncation , M @-@ 81 has ended at its junction with M @-@ 13 north of downtown Saginaw . In 2006 , MDOT completed the reconstruction of the interchange between M @-@ 81 and I @-@ 75 / US to incorporate a pair of roundabouts along Washington Road . 
 
 = = Major intersections = = 
 
 
 