 By 1900 , only a short stretch of the Detroit – Howell Plank Road was still make of <unk> ; most of the other plank roads had been converted to gravel by this time . When the Michigan State Highway Department ( MSHD ) had numbered and signed highways in the state in 1919 , it applied the M @-@ 16 number to Grand River Avenue across the state between Grand Haven and Detroit . 
