High Quality Content by WIKIPEDIA articles! M-43 is a state trunkline highway in southwestern and central parts of the US state of Michigan. The highway runs from South Haven to Webberville along an indirect path through both rural areas and larger cities. The trunkline follows three overall segments: a southeasterly track from South Haven to Kalamazoo, a northeasterly course to the Hastings area and an easterly route through the Lansing area.