Even though it does not physically connect to that highway, M-231 is a scaled-down bypass of US 31 through Grand Haven. The highway is expected to reduce response times for emergency services in the area by shortening the driving distance across the Grand River. The bridge over the river, including approaches over adjacent wetlands, is the seventh-longest in the state at and sits above the river. Seven other bridges along M-231 bring the total to nearly a mile (1.6 km) for the entire highway.