Wikipedia:WikiProject U.S. Roads/Indiana/Resources/length/concurrency math

This page is to help someone find an intersection or interchange during a concurrency. (Please Note: Not every road is on the reference post book (RPB). Also note a calculator will be vary helpful and faster, but is not required.)

You will need to have this page downloaded or opened on a internet browser.

To start find the route you need to find the length for.
 * I–## for Interstate (then number)
 * U–## for U.S. Route (then number)
 * S–## for State Road (then number)

Example
The first example will be US 30: In the RPB at the interchange with I–69 you find the mileage as 128.90. Now look at the I–69 RPB for that interchange and it is 108.98, the next interchange on I–69 and US 30, is Lima Road (US 27/SR 3) at 110.64. Next subtract (minus) 110.64 from 108.98 and you get 1.66. Now added 1.66 to 128.90 and you get 130.56, this is the mileage from the Illinois state line to the interchange at Lima Road for US 30. You would do this for the rest of the interchanges. At the interchange between I–69, I–469 and US 30. on the US 30's RPB is the mileage from the Illinois state line to that interchange.

For the interchanges on I–469 and US 30, it is about the same. You find the I–469's RPB at the interchange with US 30 and I–69 (note: This is the northern terminus of I–469, but I–69 and US 30 is not the last mileage entry, Auburn Road exit ramp heads farther west.) At the interchange with I–69 and I–469 on US 30 you get 133.88 and for I–469 you get 30.57. Now find the next interchange on I–469 that would be SR 37. This interchange is 28.58 on I–469, subtract 30.57 form 28.58 and you get 1.99. Simply add 1.99 to 133.88 and you get 134.87, this is the mileage on US 30.

Some notes

 * The RPB is from 2004 so if a route newer, has been decommission, or extended routes are not in this book.
 * Some roads still have the mileage as shown going through a town, like US 31, in Indianapolis.
 * Also show work on the talk page, of the article, if the math is very involved.

Need more help
If anyone has any questions or needs help pleas contact.