Starting either at Lebanon (NW of Indi) or Martinsville (SSE of Indi) is IN 39. It is a well maintained 2 lane road that parallels the west side of Indianapolis. It crosses and has access to all major interstates that go through Indianapolis (I65, I74, I70, I69) and US highways US 40, US 36, and US 136. It does not carry a lot of traffic, but some should be expected at Interstates.
You have small towns (Monrovia, Belleville, Danville, Lizton, and Milledgville) besides the larger start and ending towns, hilled areas (remember it's central Indiana, though), sweeping curves through farm lands, suburban homes, and few twisties along the way ... all while avoiding the traffic and conjestion of Indianapolis!
Ltttle traffic, except where they is construction near I70. Hardest was traveling north in Danville, trying to turn west on US 36 for the jog. Otherwise it's well maintained, south of Danville, it was probably repaved in 2019. Sweeping turns, but also pockets of twisties. Slightly hilly (again central Indiana), few stops except in towns. Southern part rides along IN67 - a beautiful 4 lane road with forested hills of southern Indiana on one side and the White River on the other. In Martinsville, there is construction of I69 onto IN39's footprint.
Farm land, country homes (new and old), forested hills in fall are outstanding. At any interchange you can hop into Indianapolis and be there in 20 minutes. Plenty of gas along the way and restaurants in larger towns (Martinsville and Lebanon),