Truck Activity and Wait Times at International Border Crossings

Relationships between truck queuing times immediately upstream of primary inspection stations and truck volumes and inspection times are estimated at the Ambassador Bridge and Blue Water Bridge international crossing facilities. The estimations are possible because of the recent availability of queuing and inspection time data obtained through the deployment of new technologies. Since truck volumes are available only at the monthly level, truck-level queuing and inspection time data are converted to monthly values, and aggregate relationships are estimated. Relationships are estimated for each crossing facility when using a set of 54 months of data and when dividing the data into subsets that represent a past and a recent period. Despite the aggregate nature of the data, strong relationships are produced that exhibit increased queuing times with increased monthly truck volumes and queuing time-to-volume elasticities greater than one. Differences in estimated elasticities, depending on crossing facility and direction, are consistent with different roadway characteristics upstream of the inspection stations. Relations exhibiting increased queuing times with increasing inspection times are produced, and the estimated coefficients are large enough to reflect the impacts on queuing times of differences in U.S. and Canadian inspection times. Changes in estimated relations from past to recent periods are consistent with infrastructure projects and improvements at the crossing facilities.