Michigan State Route 343 is a north-south highway in Northeastern Kalamazoo County. It runs from Riverview Drive in Kalamazoo, to Michigan State Route 89, at Richland.
In January, 2019, the City of Kalamazoo and the Michigan Department of Transportation reached an agreement to turn jurisdiction of several streets with in Kalamazoo to be turned over to the city jurisdiction from the states. This eliminated BUSN Loop I-94. BUSN U.S. Rt. 131, and Michigan State Route 43 were eliminated within the city. BUSN U.S. Rt. 131 now runs as a short spur on the north of the city. Michigan State Route 43 was rerouted along U.S. Rt. 131 to Michigan State Route 89. BUSN Spur I-94 and Michigan State Route 343 were created to take the numbering of the highways the state retained where the other highways were removed. MI St Rt 343 passes through the following town in Calhoun County. Kalamazoo
MI St Rt 343is not multi-plexed in Calhoun County. MI St Rt 199 intersects the following highways in Calhoun County. Michigan State Route 89, at Richland.