Ensuring the navigational safety of LNG carriers is crucial for maintaining orderly traffic management in port waters and for reducing the environmental risks associated with maritime accidents. In recent years, numerous scholars have conducted in-depth studies on the impact of LNG vessel navigation, and corresponding traffic control strategies within port areas have been continuously optimized. This paper, based on the current LNG traffic control measures implemented in Chinese ports, analyzes the allocation of channel resources during the inbound and outbound voyages of LNG carriers. It proposes a set of quantitative models grounded in the theory of spatiotemporal consumption, including a port channel capacity calculation model, a delay time model for other vessels, and a port throughput estimation model. These models are used to quantify the extent to which LNG carrier navigation affects the efficiency of other vessels. The proposed models are applied to a case study of the Dagang Port Area in Tianjin. Results show that due to traffic control restrictions, the channel capacity during LNG carrier navigation significantly decreases compared to normal operating conditions. Based on the forecasted LNG berth throughput, the study further estimates the vessel delays caused by varying numbers of LNG carriers, and identifies the key factors contributing to reduced channel capacity under special traffic control measures. These findings provide a theoretical basis for the planning, design, and expansion of port channels.