1900s	1910s	1920s	1930s	1940s	1950s	1960s	1970s	1980s	1990s	2000s

1984
The 50 millionth vehicle crosses the Mackinac Bridge

1984
World's first unrestricted, public-use microwave landing system begins operating at Wexford County Airport in Cadillac

1986
MDOT institutes "smiley-face" road signs in construction zones

1988
Nation's largest concrete segmental bridge opens - Zilwaukee Bridge carrying I-75 over the Saginaw River.

MDOT takes computers to construction field offices for the first time when it implements the Construction Project Record Keeping System (CPRKS).