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Treatment of left-turn movements is one of the most fundamental characteristics governing intersection geometry and signal timing designs. As traffic congestion increases, the need to maximize utilization of existing lane configurations is of great importance. At some intersections, excessive queue lengths may spill out of the left-turn bay and block the through lanes, jeopardizing level of service for the entire intersection. This paper studies the operational advantages of dynamically using short stretches (ie, pockets) of opposing lanes for left-turn movements, using “pre-signals” to control vehicle entry into the contraflow pocket. Sensitivity analyses (through micro-simulation) are used to identify signal timings and lane geometries that minimize intersection delay, while simultaneously achieving reasonably safe operations. The sensitivity analyses are also used to determine which types of intersections and specifically which turn movement congestion levels, tend to achieve the most significant delay reductions when contraflow treatment is applied. If contraflow left-turn pockets can be implemented in a safe manner at the proper locations, this could be exactly the type of bottleneck mitigation solution that our congested cities desperately need.