M-146 was a state trunkline highway

Michigan Highway System

The Michigan State Trunkline Highway System is made up of all the highways designated as Interstates, U.S. Highways and State Highways in the US state of Michigan. The system is maintained by the Michigan Department of Transportation and comprises of trunklines in all 83 counties of Michigan on...

 in the US state of Michigan

Michigan

Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....

 that served as a by-pass for traffic going around Port Huron

Port Huron, Michigan

Port Huron is a city in the U.S. state of Michigan and the county seat of St. Clair County. The population was 30,184 at the 2010 census. The city is adjacent to Port Huron Township but is administratively autonomous. It is joined by the Blue Water Bridge over the St. Clair River to Sarnia,...

, and a short cut for traffic between US 25

U.S. Route 25

U.S. Route 25 is a north–south United States highway that runs for from Brunswick, Georgia to the Ohio state line in Covington, Kentucky.-Georgia:...

 and M-21

M-21 (Michigan highway)

M-21 is an east–west state trunkline highway in the US state of Michigan connecting the cities of Grand Rapids and Flint. The highway passes through rural farming country and several small towns along its course through the Lower Peninsula...

.

Route description

At its greatest extent, M-146 began at an intersection with US 25

U.S. Route 25

U.S. Route 25 is a north–south United States highway that runs for from Brunswick, Georgia to the Ohio state line in Covington, Kentucky.-Georgia:...

 on the south side of Port Huron

Port Huron, Michigan

Port Huron is a city in the U.S. state of Michigan and the county seat of St. Clair County. The population was 30,184 at the 2010 census. The city is adjacent to Port Huron Township but is administratively autonomous. It is joined by the Blue Water Bridge over the St. Clair River to Sarnia,...

. It ran north along the west side of the city, on 24th Street, through M-21 and north eastward to the base of the Blue Water Bridge

Blue Water Bridge

The Blue Water Bridge is a twin-span international bridge across the St. Clair River that links Port Huron, Michigan, USA and Sarnia, Ontario, Canada...

 which led into Ontario, Canada. The portion north of M-21 (Lapeer Road) was built to freeway standards.

History

When the route debuted in 1933 it served as a connector between US 25 and M-21 along the west side of Port Huron. In 1954 a new approach was built from M-21 to the foot of the Blue Water Bridge. M-146 was designated along this route. In 1958, this portion was converted to freeway specifications and in 1964, with the completion of the I-94/US 25 freeway, M-146 was removed from that portion of the route. However, the M-146 designation remained along the stretch of freeway which now serves as the exit 274 interchange on I-94, but was removed from 24th street through town. In 1966, with the completion of a new freeway alignment for M-21 between Wadhams and downtown Port Huron, the M-146 designation is removed from state trunkline system and hasn't been used since.

Major intersections