M-231 Asphalt Challenge Mystery Cache

With the state's economy rebounding more slowly than expected during the first decade of the 2000s, MDOT announced on March 13, 2006 a revision in the overall plan to complete the proposed US-31 Bypass in Ottawa Co. Instead of building the entire corridor from north to south, segment after segment, the state altered their plans instead to only construct one of the proposed two Grand River spans in the 120th Ave corridor and completing a two-lane, limited-access highway from I-96 (at Exit 9) & M-104 near Nunica southerly across the river, ending at M-45/Lake Michigan Dr. This two-lane expressway was built on a four-lane freeway right-of-way to accommodate its eventual conversion to a fully controlled-access facility in the future. Also changed was the highway's route designation. Since it would not connect directly with US-31, it was designated M-231 instead—a nod to its originally-intended route number and possible future designation should the remainder of the freeway ever be constructed. M-231 serves as a relief and detour route when the US-31 Grand Haven Drawbridge is stuck in the open position or experiences other mechanical problems.