Truck survey methods vary in the response rates they generate and in their coverage, accuracy, and cost. Roadside intercept/interview surveys enjoy representation, coverage, and response-rate advantages compared with phone/mail surveys, but in practice they are frequently restricted to weigh stations, toll plazas, and similar controlled facilities. A roadside truck interview survey for Berks County, Pa. was conducted within the stream of traffic in conjunction with distribution of a postcard automobile survey. Over 1,000 interviews conducted throughout the county at five cordon locations representing key two-lane and four-lane roads were compiled. The sampling rate exceeded 22 percent, and valid response rates were approximately 98 percent. The information obtained was limited in detail but was sufficient to achieve the study objectives of estimating major internal-external, external-internal, and external-external truck movement patterns for Berks county. The study was not intended to identify internal-internal trips. The purpose, methodology, and advantages and disadvantages of the approach are discussed, and the focus is on the traffic congestion element. Surveys were conducted within a single lane in each direction, restricting traffic flows. At certain traffic volumes (roughly 200 vehicles per 15 min) delays became a significant problem, including several periods during which surveys were not conducted to alleviate traffic backups. The conclusion suggests using this parameter for applying the method to other locations.