This study focuses on optimizing toll plaza design by considering queue areas and the required number of lanes. Data from seven Indian toll plazas, collected at five-minute intervals, were used to establish a linear relationship between average and maximum queue length. Additionally, Level of Service (LOS) thresholds were developed based on queue length using k-means clustering. Notably, the study takes into account queued vehicles, making it easier to estimate vehicle counts in real field conditions. Findings indicate that for design LOS-C, the queue area should be 102.00–174.24 m long. Queue length is also linked to queue delay, aiding in tollbooth clearance time determination. Furthermore, the study assesses the impact of increasing Electronic Toll Collection (ETC) usage, known locally as FASTag, on the required number of toll lanes. This research serves as a valuable resource for field engineers designing queue areas and toll lanes, addressing current traffic conditions.