Radio Communications for the Western Transportation Institute’s Augmented Speed Enforcement Project

The purpose of the augmented Speed Enforcement (aSE) project was to detect and warn speeding vehicles in a work zone and provide warnings to work zone workers. The system developed by Montana State University consists of 28 orange traffic drums (called smart drums or sDrums) that were positioned adjacent to the orange cones marking the work zone lane closure. When the system detects a speeding vehicle approaching, it synchronously flashes the orange lights on top of the drums, warning the driver to slow down and the workers of a speeding vehicle. If the vehicle speed is above a set trigger speed, the system activates a pager system that warns the workers of the speeding vehicle. The sDrum system used a Digi XBee adaptor mesh radio for communications which is the focus of this report. Basic antenna pattern and range measurement were performed to validate the published range. The outdoor range was measured as 200 feet. That is much less than the 1 mile outdoor range published by the manufacturer and even less than the 300 feet indoor published range. This report contains the full results of the radio tests performed.