The highway is named for former Indiana governor Frank O'Bannon, who died after suffering a stroke in 2003 with 16 months remaining in his second and final term. O'Bannon, a Corydon Democrat, who was first elected to the Indiana General Assembly as a State Senator in 1970, had long supported an improved highway linking to Interstate 64. This position greatly endeared him to his constituents, who had long dealt with narrow, winding and somewhat dangerous two-lane highways connecting them to the rest of the state. The SR 37/145 Association, which is made up of community and government leaders from Perry, Crawford, Orange and Lawrence counties, considered O'Bannon a strong ally in getting better and faster access to I-64 for their communities. Following his death, the association lobbied the state of Indiana to name the highway in his memory.
On November 21, 2007, the last unfinished segment of the highway opened between St. Croix and Eckerty. The new portion, a stretch of highway numbered as SR 37, was built as a "super-two" roadway, matching the existing stretch of SR 37 to which it connects at I-64, as well as that of SR 64 and SR 145 which continue the route from Eckerty to French Lick.
Improvements to the various segments through the years
From Bedford to Indianapolis, SR 37 had been upgraded to four lanes by the early 1980s. South of Bedford, the road remained two lanes. This changed when the state widened an additional of the highway from just south of Mitchell to the west junction with US 50 south of Bedford to four lanes. From Paoli to Mitchell, the road is still a two-lane facility, but it is in relatively good condition and congestion is seldom an issue. However, traffic in Paoli itself is forced to negotiate the town square, which generally resembles a roundabout. From Paoli to the south and west, the highways are narrow and winding.
Orange County's tourist boom may necessitate more improvements
, which has a storied history—illegal gambling flourished along with the mineral springs in the early years of the 20th century in West Baden and French Lick—is in the midst of a tourism rebirth. The new French Lick Resort Casino and the restoration of both the French Lick Springs Hotel and West Baden Springs Hotel have drawn many thousands of visitors. In addition, during the winter months, Ski Paoli Peaks, a popular snow-skiing park in Paoli, also draws thousands of tourists. With additional people on the roads, Orange County officials and the Indiana 37/145 Association are seeking to have the state make more improvements to the SR 56/US 150 leg of the highway.
Future
The Indiana 37/145 Association continues to lobby for improvements to SR 56 and US 150 from French Lick to Paoli. Aside from spot improvements at intersections and bridges, the Indiana Department of Transportation does not plan to make major changes to that segment. The first of the improvements are set for construction in 2009. The association continues to lobby for the original plan—making SR 56 and SR 150 into a "super-two"—as traffic generated by the new French Lick Resort Casino was not taken into consideration when the plan was scrapped by INDOT. A by-pass of Paoli, which has been tentatively numbered as SR 237, is one of the state's Major Moves projects scheduled to begin construction in 2012. This segment of SR 237 will likely become part of the Frank O'Bannon Highway.
