Assessing the Effects of Benefits and Institutional Influences on the Continued Use of Environmentally Munificent Bypass Systems in Long-Haul Trucking

Figure A1 illustrates how bypass systems operate. Drivers and/or companies who subscribe to a commercial bypass service install wireless transponders (serving as the sensors for the network) onto the windshield of their trucks. Transponders are provided free of charge by the bypass system company. As the truck approaches a weigh station equipped with the corresponding bypass system, information pertaining to vehicle weight is transmitted to the station. The receivers are mounted on elevated “booms” positioned over the highway between one half-mile to one mile before the station (point 1 in Figure A1). Truck and driver data are forwarded to the weigh station (point 2) and checked for compliance. If the weight, driver service hours, and other data are within acceptable limits, then a signal is sent to and broadcast from a second elevated boom (point 3) that illuminates a green light on the truck’s transponder giving the driver permission to bypass that station (point 4). If data are not acceptable, a signal illuminating a red light is broadcast (at point 3) and the driver must pull into the weigh station (point 5). Trucks may still be selected for a random inspection (point 2), resulting in a red light appearing on the transponder (point 3) and a required stop for the driver (point 5) (Regan et al. 2006). Conversely, all trucks without transponders are required to stop at the station for inspection. As with the transponders, the bypass system company furnishes and installs the receivers for the state transportation agencies. The only costs to the users are the monthly subscription fees for the service that are marketed to carriers or to individual drivers. Subscriptions are available only to carriers or individual drivers with good safety records.