Two-stage turn queue boxes (TSTQB) are innovative bicycle infrastructure treatments implemented to enhance bicyclist safety and comfort. These boxes provide an alternative for bicyclists to make left turns from right-side cycle tracks or bike lanes and right turns from left-side cycle tracks or bike lanes at multi-lane intersections. The aim of this treatment is to improve bicyclist visibility and predictability and protect bicyclists' left-turning movements, thus reducing crash risk. Although these solutions are being implemented at various intersections throughout the USA, research on the behavior of bicyclists in the presence of TSTQB is limited. There is a need to investigate the way TSTQBs are used and understand which design characteristics may influence their effectiveness in improving bicyclist safety. This thesis addresses this research gap by collecting real-world data from six intersections in the Greater Boston area featuring TSTQBs and providing an in-depth examination of left-turning bicyclist behavior in the presence of such treatments. A comprehensive inventory of TSTQBs in Massachusetts is first presented. The inventory has been collected through manual observations from Google Maps. The analysis focuses on understanding bicyclists’ positioning and usage rates of TSTQBs in the presence of left-turn phases, dedicated left-turn lanes, and bike boxes. Finally, correlations between intersection and TSTQB design characteristics and bicyclist behavior are examined. The final outcomes of this study can serve as a basis for informing design standards and educational initiatives that aim to enhance bicyclist safety at signalized intersections.