Traffic Delays at Toll Booths

The collection of vehicular tolls at Port Authority tunnels and bridges is one of the most important operations conducted by the police personnel. More than 250 traffic officers are utilized, and the payroll costs exceed a million dollars annually. In staffing its toll plazas the Port Authority attempts to handle traffic with a minimum number of toll collectors consistent with uniformly good service to the public and properly spaced relief periods for the toll collectors. This requires finding the level of traffic delays that gives the best compromise between the conflicting objectives of economy and service. In the past the number of toll collectors provided for operating a toll plaza was determined by judgment based on experience and a rule-of-thumb work standard which had not been related to service. Judgment was likewise used to allocate manpower and control the number of toll booths opened at any time. This method resulted in patron delays observed to vary from 2 to 50 sec. The tools of probability theory provide methods for dealing with the problem in quantitative terms. They enable determination of the relations between traffic volumes, number of toll booths, and grade of service. With this knowledge the optimum grade of service can be established in a logical manner and the number of toll booths required at any time of day can be specified in advance. Use of this method permitted savings in toll collection expenses and better service. Operations Research , ISSN 0030-364X, was published as Journal of the Operations Research Society of America from 1952 to 1955 under ISSN 0096-3984.