SR 4B was constructed in the early 1970s by ODOT to allow for easier travel between Cincinnati and Middletown. In the 1990s, the Butler County Transportation Improvement District (BCTID) was formed to help address traffic congestion along the fully two-lane bypass route. Construction started on the widening of SR 4B in 2010 which included the widening of the road from the southern terminus to SR 129, the widening of three bridges, and the creation of three superstreet and one quadrant roadway intersections. The superstreet intersections were completed in 2011. Construction of the expanded roadway finished in August 2012 on time and on budget, at a cost of $22.8 million. The BCTID is continuing to study the option of widening SR 4B north of SR 129. SR 4B is the first superstreet corridor in Ohio. As of April 2013, it was reported that the majority of motorists in the area did not approve of the new design, with some avoiding SR 4B entirely.