text: business routes of interstate 75 in michigan there have been nine business routes for interstate 75 in the us state of michigan . numbered either business loop interstate 75 ( bl i - 75 ) or business spur interstate 75 ( bs i - 75 ) depending if they are a full business loop or a business spur , these highways are former routings of i - 75 's predecessor highways in the state . they were designated as i - 75 was completed through the various areas of michigan . the business loop in pontiac runs through that city 's downtown along a section of woodward avenue and a segment of roadway formerly used by m - 24 . the former saginaw business loop was once a part of us highway 23 ( us 23 ) , as was most of the original bay city business loop . the roadways that make up the business loops in west branch and roscommon were previously part of m - 76 , i - 75 's predecessor through that part of the state . in northern michigan , the grayling and gaylord bl i - 75s were part of us 27 , and the two business routes in st. ignace and sault ste . marie in the upper peninsula of michigan were part of us 2 . each of the business loops connects to i - 75 on both ends and runs through their respective cities ' downtown areas . the two business spurs only connect to i - 75 on one end and run into the appropriate downtown . pontiac business loop i - 75 ( bl i - 75 ) is a business loop serving pontiac and auburn hills . it uses portions of former business m - 24 ( bus . m - 24 ) through town . the highway starts as an eight - lane freeway at an interchange on i - 75 in bloomfield township . the freeway continues past an interchange with opdyke road to end at square lake road , dropping to six lanes . bl i - 75 continues to m - 1 at woodward avenue . square lake road continues to the west as bus . us 24 , bl i - 75 turns northwesterly along the eight - lane divided woodward avenue , running concurrently with bus . us 24 into downtown pontiac . at the south side of downtown , woodward drops to six lanes the two directions of woodward avenue split and form a four - lane loop . the woodward avenue loop encircles downtown pontiac , and it is crossed by the eastbound direction of m - 59 running on huron street . one block north , the westbound direction of m - 59 runs along university drive and turns to follow bl i - 75 / bus . us 24 ( woodward avenue loop ) . the loop intersects perry street another block further north , and bl i - 75 turns northeasterly onto the two - way perry street . bl i - 75 passes through residential areas and a minor business area along the four - lane perry street . outside of the downtown area , perry street widens to include a center turn lane . north of walton boulevard in auburn hills , the street name changes to lapeer road . bl i - 75 intersects opdyke road a couple hundred feet west of i - 75 before crossing the freeway . lapeer road continues as a six - lane , divided roadway to the ramps of a double trumpet interchange , where the bl i - 75 designation ends . the roadway however , continues as m - 24 providing access to the palace of auburn hills . on average each day in 2013 , 9 , 829 vehicles use the business loop between the two m - 59 junctions , and 73 , 795 vehicles do so on the freeway stub east of opdyke road , the lowest and highest traffic counts . in 1919 when the state highway system was first numbered , the main north – south highway through pontiac was numbered m - 10 , and it was renumbered to us 10 seven years later when the united states numbered highway system was created . by the next year , m - 24 was designated from downtown pontiac northward to lapeer . m - 24 was moved to an eastern bypass of town in 1936 , and the former routing in town became m - 24a . this was redesignated bus m - 24 in 1940 . a number of highway designation and routing changes in the pontiac were made when us 10 was shifted out of downtown to replace m - 58 along telegraph road west of downtown by the middle of 1961 . before the change , us 10 followed dixie highway and oakland avenue southeast into pontiac to perry street and then perry to woodward while m - 58 was routed along telegraph and square lake roads . after the change , us 10 turned south from dixie highway onto telegraph and then east onto square lake to connect back to woodward . the old route through downtown was assigned the bus . us 10 moniker and m - 58 was decommissioned as a highway designation . two years later , i - 75 was completed to the east of pontiac , and the m - 24 bypass of the city was turned over to local control . the former bus . m - 24 through downtown was renumbered bl i - 75 along with a connection along square lake road out to the freeway . the next year , the streets downtown pontiac were reconfigured and a loop called wide track drive was created to route traffic around the downtown area . the former routing of bl i - 75 on perry street in the downtown core was replaced by routing the business loops on wide track drive . then in 1966 , an interchange was built to replace the intersection at opdyke road and square lake road . in 1985 , the michigan department of transportation ( mdot ) received permission from the american association of state highway and transportation officials to truncate us 10 to bay city , and when the change was made the following year , us 24 replaced us 10 on telegraph road north of square lake road , and bus . us 10 through downtown was redesignated bus . us 24 , including the segment concurrent with bl i - 75 . wide track drive through downtown was renamed as the woodward avenue loop in 2000 . the section of bl i - 75 that follows woodward avenue has a pair of special designations attached to it . in 1999 , it was designated by mdot as what is now called a pure michigan byway . three years later , it was named a national scenic byway by the federal highway administration national scenic byways program on june 13 , 2002 , the only urban road at the time with that classification . it was later upgraded to all - american road status on october 16 , 2009 . major intersections the entire highway is in oakland county . saginaw business loop i - 75 ( bl i - 75 ) was a business loop in saginaw that was previously business us highway 23 ( bus . us 23 ) . it started at an interchange between i - 75 / us 23 and m - 46 ( holland road ) in buena vista township . from there , it ran concurrently with m - 46 westward into saginaw . east of 17th street , the highway split to form a one - way pairing with remington street , which carried westbound traffic . about three blocks further west , bl i - 75 split from m - 46 to follow genesee avenue northwesterly into the downtown area . at an intersection between genesee avenue , janes street and 2nd avenue , the northbound bl i - 75 followed 2nd avenue while southbound continued on genesee avenue . northbound traffic traveled along 2nd avenue and johnson street to washington avenue near the saginaw river , where the two directions of traffic reunited . washington avenue also carried m - 13 / m - 81 , and the three designations ran concurrently together northward and parallel to the river . bl i - 75 / m - 13 / m - 81 curved northeasterly north of downtown , and m - 81 left the business loop at an intersection with veterans memorial parkway ; bl i - 75 / m - 13 turned north on the parkway and m - 81 continued easterly on washington avenue . the business loop proceeded northward running parallel to the river and ended at an interchange with i - 75 / us 23 in zilwaukee township ; m - 13 continued along bay city road north of the interchange . when the state highway system was signposted in 1919 , the north – south highway through saginaw was part of the original m - 10 . this highway was later redesignated as part of us 23 when the united states numbered highway system was created in 1926 . us 23 was initially routed on the western side of the saginaw river through the city , but it was moved in 1929 to run along the eastern side . in 1953 , the initial eastern bypass of saginaw was built as a two - lane highway , and the former routing through downtown was redesignated bus . us 23 . this bypass was upgraded in 1961 to a full freeway as part of i - 75 / us 23 , and the business loop through downtown was redesignated bl i - 75 . in 1971 , i - 675 was completed , and bl i - 75 was decommissioned through saginaw . the segments of the business loop that were concurrent with m - 13 , m - 46 or m - 81 remained part of those state highways , but the rest of bl i - 75 was returned to local control . major intersections the entire highway was in saginaw county . bay city business spur interstate 75 ( bs i - 75 ) is a business spur running through bay city following a section of the current routing of m - 25 through town . formerly a full business loop numbered business loop interstate 75 ( bl i - 75 ) , it followed what is now m - 84 back to end at i - 75 / us 23 at exit 160 south of downtown . the business route also follows streets that previously were numbered business us highway 23 ( bus . us 23 ) . the spur starts at exit 162 on i - 75 / us 23 at the same interchange where m - 25 and us 10 end . bs i - 75 runs concurrently along m - 25 , and for about the first 1 1 ⁄ 3 miles ( 2 . 1 km ) , the spur is a four - lane freeway bounded by residential subdivisions on either side . in bangor township , the freeway ends and bs i - 75 / m - 25 splits into a one - way pairing of thomas street ( eastbound ) and jenny street ( westbound ) . these two three - lane streets continue along a residential area on the west side of bay city . east of intersections with henry street , the opposing sides of traffic merge back together near veterans memorial park to cross the saginaw river on the four - lane veterans memorial bridge . on the eastern side of the river , bs i - 75 / m - 25 splits again into the one - way pairing of the three - lane mckinley street ( westbound ) and 7th street ( eastbound ) . just three blocks east of the river , bs i - 75 ends at the intersections with m - 84 ( washington avenue ) in downtown bay city . on average each day in 2013 , 11 , 678 vehicles use the business loop east of the m - 13 junction , and 29 , 391 vehicles do so west of the m - 84 junction , the lowest and highest traffic counts . when the state highway system was first signposted in 1919 , the north – south highway through bay city was part of the original m - 10 , and the east – west highway was numbered as part of m - 20 . when the united states numbered highway system was created in 1926 , m - 10 became part of us 23 , although it was routed on the western side of the saginaw river . the highway was rerouted to the eastern side of the river in 1929 . by early 1941 , us 23 was rerouted to cross the saginaw river on the southern side of bay city , and the former routing along washington avenue and midland street through downtown was renumbered bus . us 23 . when the i - 75 / us 10 / us 23 freeway bypass west of bay city opened in late 1961 , the former routing of us 23 was replaced by m - 13 and the former bus . us 23 , including connections along the former routing of m - 47 southwest and m - 20 west of bay city , were redesignated as bl i - 75 . the bl i - 75 designation lasted until 1971 when southern half of bl i - 75 was removed , converting the business loop into a business spur ; the southern section was renumbered as part of an m - 84 extension , and bs i - 75 would then run along the section concurrent with m - 25 only . major intersections the entire highway is in bay county . west branch business loop interstate 75 ( bl i - 75 ) is a business loop running through west branch that was originally numbered business m - 76 ( bus . m - 76 ) . it starts at exit 212 south on i - 75 south of west branch . from that interchange , bl i - 75 runs northward along cooks road in horton and west branch townships past an outlet mall . north of the mall , the roadway has two lanes , one in each direction plus an intermittent center turn lane , and it curves first to the northeast through a rural section of the townships , and then after intersecting old 76 road , it turns northwesterly through a commercial area . on the eastern city limits , bl i - 75 turns due west and runs concurrently with m - 55 on the four - lane houghton avenue through downtown west branch . on the western side of downtown , the business loop intersects the northern end of m - 30 and narrows to two lanes . bl i - 75 / m - 55 continues out of town , running past more businesses before meeting i - 75 at exit 215 . at that interchange , bl i - 75 ends , and m - 55 merges onto the freeway . on average each day in 2013 , 10 , 682 vehicles use the business loop near the southern i - 75 interchange , and 15 , 399 vehicles do so between the m - 55 junction and 5th street in downtown west branch , the lowest and highest traffic counts . when the state highway system was signposted in 1919 , the highway running northwest – southeast through west branch was numbered m - 76 and the east – west highway was m - 55 . in the early 1970s , m - 76 was being converted into a freeway between standish and the grayling area . in 1970 , the freeway was built as far as the present - day exit 212 , and the connection along cook road was built to allow m - 76 to connect between the new freeway and its former routing . the next year , this freeway was completed to bypass west branch to the south and west . the former route of m - 76 through town with the connection along cook road was renumbered bus . m - 76 . two years later , i - 75 was finished in the state , and the m - 76 designation was decommissioned . the former bus . m - 76 was redesignated as bl i - 75 at the same time . major intersections the entire highway is in ogemaw county . roscommon business loop interstate 75 ( bl i - 75 ) is a business loop running through roscommon . starting at exit 239 along i - 75 , the business loop runs concurrently with m - 18 northward along the two - lane roscommon road through rural northern michigan woodlands . when bl i - 75 / m - 18 enters the village of roscommon , it follows lake street northeasterly into downtown . at the intersection with 5th street , bl i - 75 turns northwesterly and separates from m - 18 . in the village , the business loop has three lanes , one in each direction with a center turn lane . the business loop continues past several businesses and exits the village as a two - lane road . bl i - 75 curves to run due west along the roscommon – crawford county line on federal highway . at exit 244 on i - 75 , the business loop terminates while following the county line . on average each day in 2013 , 1 , 531 vehicles use the business loop near the northern i - 75 interchange , and 5 , 987 vehicles do so in downtown roscommon south of the m - 18 junction , the lowest and highest traffic counts . when the state highway system was originally signposted in 1919 , the highway running northwest – southeast through roscommon was numbered m - 76 . in 1949 , m - 18 was extended north into roscommon and then west along m - 76 . during the early 1970s , m - 76 was being converted into a freeway to be used as part of i - 75 . in 1971 , i - 75 was completed southward from the grayling area to what is now exit 239 . two years later , i - 75 was completed between roscommon and west branch , and m - 76 between the two communities was decommissioned . at the same time , m - 18 was realigned to northeasterly out of roscommon instead of following m - 76 toward grayling . bl i - 75 was commissioned at this time to overlap m - 18 from the freeway north into roscommon and to replace the former m - 18 / m - 76 west of the village to the new freeway . major intersections grayling business loop interstate 75 ( bl i - 75 ) is a business loop running through grayling . the southern end is at a partial interchange at exit 254 on i - 75 ; only northbound i - 75 traffic can access northbound bl i - 75 , and southbound bl i - 75 traffic can only access southbound i - 75 . from this interchange , the business loop runs northward as a five - lane divided roadway through a commercial area and past the grayling golf club . at the intersection with huron street ( south down river road ) , bl i - 75 merges with m - 72 . the two highways run concurrently and turn northwesterly along the five - lane undivided james street . bl i - 75 / m - 72 narrows to three lanes and crosses the au sable river and runs for about 3 ⁄ 4 mile ( 1 . 2 km ) before intersecting lake street in downtown grayling . there , m - 72 turns southwesterly onto lake street , separating from the business loop . at the same intersection , m - 93 turns north and merges with bl i - 75 as the two run concurrently on the three - lane mcclellan street . bl i - 75 / m - 93 intersects f - 32 ( north down river road ) and then passes the camp grayling airfield . north of the airfield , the highway narrows to two lanes and curves to the northwest , exiting the city . at the intersection with old 27 and hartwick pines road , bl i - 75 / m - 93 turns northeasterly onto the latter . they continue running concurrently to exit 259 on i - 75 where the bl i - 75 designation terminates . m - 93 continues along hartwick pines road north of the interchange . all of bl i - 75 through grayling is a part of the strategic highway network , a component of the national highway system , a network of roads important to the country 's economy , defense , and mobility . on average each day in 2013 , 1 , 407 vehicles use the business loop between old 27 and i - 75 , and 18 , 467 vehicles do so in downtown grayling south of the m - 72 junction , the lowest and highest traffic counts . when the state highway system was originally signposted in 1919 , the north – south highway through grayling was part of the original m - 14 . at that time , m - 93 was only a spur from downtown grayling to the future camp grayling . it was later redesignated as part of us highway 27 ( us 27 ) in 1926 . by 1932 , m - 93 was extended northward through grayling to the state park . in 1940 , m - 72 was extended through the grayling area . i - 75 in the grayling area opened in 1961 and , the former routing of us 27 through grayling northward to hartwick pines road back to i - 75 was redesignated bl i - 75 . major intersections the entire highway is in crawford county . gaylord business loop interstate 75 , or bl i - 75 is a business loop running through gaylord . the loop starts at exit 279 on i - 75 in bagley township south of gaylord . the highway follows the five - lane otsego avenue northward from the freeway into the city and though a commercial area . otsego avenue jogs eastward slightly south of 2nd street , and then intersects m - 32 ( main street ) in downtown gaylord . bl i - 75 turns west onto the five - lane main street and runs concurrently with m - 32 through downtown . about five blocks each of that turn , bl i - 75 / m - 32 meets i - 75 at exit 282 ; bl i - 75 ends while m - 32 continues westward . on average each day in 2013 , 8 , 289 vehicles use the business loop south of the m - 32 junction , and 23 , 436 vehicles do so in downtown gaylord along the m - 32 concurrency , the lowest and highest traffic counts . when the state highway system was first signposted in 1919 , the main highway running north – south through gaylord was part of the original m - 14 . this was renumbered as part of us highway 27 ( us 27 ) in 1926 after the united states numbered highway system was formed . i - 75 was completed and us 27 was removed through the gaylord area in 1961 . the business loop was not created at that time , however . instead , it was created in 1986 . major intersections the entire highway is in otsego county . st. ignace business loop interstate 75 ( bl i - 75 ) is a business loop running through st. ignace . the loop starts at exit 344 on i - 75 as the continuation of us highway 2 ( us 2 ) into downtown . the highway carries the lake huron circle tour ( lhct ) . it runs along a four - lane roadway on the north side of straits state park and curves northward into downtown st. ignace along state street . bl i - 75 and three lanes and runs along the lakefront past the marina and docks for mackinac island ferry services . it widens back to four lanes to follow the curve of east moran bay and then turns inland past several hotels situated on a point jutting into the bay . north of the point , bl i - 75 follows the lake huron shoreline past the mackinac county airport . north of the airport , the adjacent properties are primarily residential with a few tourist - oriented businesses . the business loop intersects county road h - 63 ( mackinac trail ) and comes to an end near castle rock at exit 348 on i - 75 in st. ignace township . on average each day in 2013 , 4 , 327 vehicles use the business loop near the northern i - 75 interchange , and 8 , 819 vehicles do so near the southern i - 75 interchange , the lowest and highest traffic counts . the first state highway through st. ignace was an extension of us 31 that was added by the end of 1927 . in 1936 , us 2 was realigned to run into downtown st. ignace from the west and replaced us 31 through town . the business loop was commissioned in 1960 when the i - 75 / us 2 freeway opened , and the former route of us 2 through downtown was renumbered bl i - 75 . major intersections the entire highway is in mackinac county . sault ste . marie business spur interstate 75 ( bs i - 75 ) is a business spur running through sault ste . marie . it starts at exit 392 on i - 75 on the south side of the city . from that interchange , it runs eastward along the five - lane - wide 3 mile road and intersects the northern end of county road h - 63 ( mackinac trail ) before curving northeasterly . the spur runs through commercial areas and intersects the northern end of m - 129 ( dixie highway ) before turning due north along ashmun street near the sault ste . marie municipal airport . ashmun street narrows to four lanes north of 10th avenue and regains a center turn lane at adams avenue . bs i - 75 turns northeasterly onto the two - lane avenue and runs to the east of the campus of lake superior state university , crossing the edison sault power canal . at portage avenue south of the soo locks . , bs i - 75 turns southeasterly to follow portage avenue along the st. marys river . the spur crosses the canal just upstream from its mouth . portage avenue continues through residential neighborhoods on the east side of sault ste . marie , following the river . bs i - 75 ends at the entrance to the sugar island ferry dock across from the sault ste . marie country club . on average each day in 2013 , 1 , 433 vehicles use the business loop near the i - 75 interchange , and 19 , 962 vehicles do so north of the m - 129 junction , the lowest and highest traffic counts . when the state highway system was first signposted in 1919 , the north – south state highway in sault ste . marie was numbered m - 12 in 1919 . it was renumbered as part of us highway 2 in 1926 . in 1962 , the i - 75 / us 2 freeway was completed , and the former route of us 2 through downtown along with a connection between i - 75 / us 2 and the international bridge was redesignated bs i - 75 . in 1989 , the designation was extended along portage avenue to the sugar island ferry dock . major intersections the entire highway is in sault ste . marie , chippewa county .