The Electric Reliability Council of Texas (ERCOT) operates as an isolated grid, making it highly susceptible to generation shortages and congestion issues. The proposed interregional transmission expansion, as outlined in the Connect the Grid Act, has the potential to enhance grid reliability, market efficiency, and renewable integration. This research aims to quantify the reliability benefits of new transmission lines by evaluating their impact on resource adequacy, system resilience, and blackout risk mitigation. The study will use production cost modeling combined with power flow analysis to assess how increased interregional connectivity can improve grid stability and energy security in ERCOT.