Take your interstate exit number and add 200.
That’s the simple formula the Indiana Department of Transportation created to renumber all of the mile markers and exits along Interstate 69 to compensate for the extension of the freeway south to Evansville.
State officials on Wednesday announced their plans for changing the interstate’s mile markers at a meeting at the Greater Fort Wayne Chamber of Commerce.
Because the state is adding nearly 200 miles of I-69 south of Indianapolis, the northern section of the freeway must be renumbered to meet federal guidelines. Such interstates must start at mile No. 0 at their southern end and count up as it moves north.
For example, under the new system, Exit 99 for the Fort Wayne International Airport will become Exit 299.
The state will begin changing the signs Aug. 6 in the Fort Wayne area starting at the Michigan state line and moving south. In the Greenfield area, crews will begin in Indianapolis and move north, with crews turning around and moving in the opposite direction at the boundary of the two districts. The process is expected to take about two months to complete.
It will cost about $250,000 to create new signs and install them, although the state will use its own crews to do the work.
While mile-marker signs will be replaced completely, exit signs will still contain reminders of their old exit numbers. Those old number signs will be maintained until 2015 and will be completely removed by Oct. 1, 2017.