The document discusses various aspects of toll plaza design and operation. It describes how tolls are collected to recover construction and maintenance costs. It also discusses different toll collection methods like manual, coin machines, and electronic toll collection. The optimal number of toll booths is determined using queuing theory to minimize total delay time from queuing and merging. Level of service for toll plazas is based on density and volume-to-capacity ratios. Numerical examples calculate total delay times and the optimum number of toll booths given traffic flow and toll booth parameters.