Often, road construction requires that work zones be created and shielded by portable concrete barriers (PCBs) to protect workers and equipment from errant vehicles as well as prevent motorists from striking other roadside hazards. For an existing W-beam guardrail system installed adjacent to the roadway and near the work zone, guardrail sections are removed in order to place a PCB system. The focus of this research study was to develop a crashworthy transition between W-beam guardrail and PCB systems. This research effort was accomplished through development and refinement of design concepts using computer simulation with LS-DYNA. Additionally, a Critical Impact Point (CIP) study was conducted to determine impact locations for full-scale crash testing. The design effort resulted in a new system consisting of a Midwest Guardrail System (MGS) which overlapped a series of F-shape PCB segments placed at a 15:1 flare. In the overlapped region of the barrier systems, uniquely-designed blockout supports and a specialized W-beam end shoe mounting bracket were used to connect the systems. Three full-scale vehicle crash tests were successfully conducted according to the AASHTO Manual for Assessing Safety Hardware (MASH) Test Level 3 (TL-3) safety performance criteria. Based on the successful test results, a MASH TL-3 crashworthy guardrail to PCB transition system is now available for protecting motorists, workers, and equipment found in work zones.