Indiana State Road 431
|Maintained by INDOT|
|Length:||20.0 mi (32.2 km)|
|Madison Avenue segment|
|Length:||8.4 mi (13.5 km)|
|South end:||US 31 in Greenwood|
|North end:||US 31 at Indianapolis|
|Keystone Avenue segment|
|Length:||11.6 mi (18.7 km)|
|South end:||SR 37 in Indianapolis|
|I-465 / US 31 / US 52 / US 421 in Indianapolis|
|North end:||US 31 at Carmel|
|Counties:||Johnson, Marion, Hamilton|
The former State Road 431, now simply Keystone Avenue, remains a busy route connecting U.S. Route 31 with Interstate 465 at Exit 33. It passes through the Indianapolis suburb of Carmel, allowing traffic on U.S. 31 north of Carmel a shorter route to I-465 and the east side of Indianapolis. Until the 1990s, the State Road 431 designation extended south of I-465 to 86th Street. Prior to that, it also continued south along N. Keystone Avenue to S.R. 37 at Fall Creek Parkway, North Drive in Indianapolis.
Beginning at a junction with US 31 in Greenwood, SR 431 traveled along Madison Avenue northwest to the south side of Indianapolis. While on Madison Avenue, SR 431 passed through a mix of residential and commercial properties. The suburban surroundings dominated much of the route until it began to encroach on the outskirts of Indianapolis. The highway terminated at US 31, now East Street, in Indianapolis.
Beginning at a junction with SR 37 just northeast of downtown Indianapolis, SR 431 traveled north along Keystone Avenue. While on Keystone Avenue, SR 431 passed through a mix of residential and commercial properties. The highway passed through an interchange with 86th street (formerly SR 100) and Interstate 465. The highway terminated at US 31 in Camel.
SR 431 was officially decommissioned on October 19, 2007, with the portions north of 96th Street being turned over to the city of Carmel. Carmel Mayor James Brainard immediately proposed banning heavy trucks from the route, the Hamilton County portions of which lies within his city's corporate limits. He also pushed for a plan to build six roundabout-style ("dogbone") interchanges on Keystone, built 2009–2010, in lieu of widening it to at least six travel lanes throughout.
Further south in Marion County, a former southern portion of S.R. 431 extended south along Madison Avenue from the south side of Indianapolis through Greenwood. Madison Avenue, which was the original routing of U.S. 31 on Indy's south side, does not have an interchange with I-465, however. The northern terminus of this section was at Madison's intersection with East Street, which used to carry U.S. 31 to the south. The southern terminus was where Madison merges with existing U.S. 31 alignment in Johnson County just south of Smith Valley Road, south of Greenwood Middle School.
|Gap in route|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi
- Microsoft. "Indiana State Road 431". Bing Maps (Map). Cartography by Nokia. http://www.bing.com/maps/#Y3A9MzkuODA2MTExfi04Ni4wODY4NTMmbHZsPTEwJnN0eT1yJnJ0cD1wb3MuMzkuODM1MTgwXy04Ni4xMjE3MjdfbmVhciUyME4lMjBLZXlzdG9uZSUyMEF2ZSUyQyUyMEluZGlhbmFwb2xpcyUyQyUyMElOJTIwNDYyMDVfX19hX35wb3MuMzkuOTk3Njc0Xy04Ni4xMjU3OTNfbmVhciUyMEtleXN0b25lJTIwUGt3eSUyQyUyMENhcm1lbCUyQyUyMElOJTIwNDYwMzJfX19hXyZtb2RlPUQmcnRvcD0wfjB+MH4=. Retrieved October 27, 2012.
- Microsoft. "Indiana State Road 431". Bing Maps (Map). Cartography by Nokia. http://www.bing.com/maps/#Y3A9MzkuNjQwNDEyfi04Ni4xMTE1NDMmbHZsPTEzJnN0eT1yJnJ0cD1wb3MuMzkuNjA0NzA3Xy04Ni4xMDcxMDlfbmVhciUyME1hZGlzb24lMjBBdmUlMkMlMjBHcmVlbndvb2QlMkMlMjBJTiUyMDQ2MTQzX19fYV9+di4zOS42MTQyMTNfLTg2LjEwOTg4MV9JTi00MzElMjAlMkYlMjBTJTIwTWFkaXNvbiUyMEF2ZX52LjM5LjY3NDgyMl8tODYuMTMwNDUyX1MlMjBNYWRpc29uJTIwQXZlfnBvcy4zOS43MjAyOTJfLTg2LjE0OTAyMl9uZWFyJTIwMzExNSUyMFMlMjBNYWRpc29uJTIwQXZlJTJDJTIwSW5kaWFuYXBvbGlzJTJDJTIwSU4lMjA0NjIyN19fX2FfJm1vZGU9RCZydG9wPTB+MH4wfg==. Retrieved October 27, 2012.
- "Daniels announces agreement to transfer ownership of Keystone Avenue" (Press release). Indiana Department of Transportation. Retrieved September 6, 2007.
- The Associated Press (September 8, 2007). "Carmel gets road, state pays". Post-Tribune. p. A6. OCLC 2266386. Retrieved October 29, 2012.