Portable Non-Intrusive Traffic Detection System (PNITDS)

Project Description

Traditional traffic data-collection methods, such as inductive loops and road tube counters, require intrusion into the roadway to install. This creates traffic interruptions and safety concerns as personnel are exposed to traffic during installation. This project developed an accurate, simple, cost-effective, portable and safe method of collecting traffic. The “Portable Non-Intrusive Traffic Detection System” (PNITDS) TPF-5(171) provided an alternative to conventional methods by allowing agencies to collect data in high-traffic locations without compromising traffic flow or personnel safety.

The Minnesota Department of Transportation (Mn/DOT) is the lead state in conducting the PNITDS evaluation test. The project is supported by 16 other participating state DOTs through a pooled-fund effort. The purpose of this project is to provide data-collection practitioners with a cost-effective PNITDS system design. The project fabricated and field-tested a prototype system. This system was then demonstrated to participating pooled fund states for onsite training. The selected design consists of a battery-powered, pole-mounted system that serves as a platform for mounting side-fired non-intrusive traffic sensors. Three sensors were evaluated: the RTMS by EIS, the SAS-1 by SmarTek, and the SmartSensor by Wavetronix. Field-test results were obtained for volume, speed and length-based vehicle classification under a variety of mounting configurations. The project also examined the ease of system setup, system reliability and flexibility. An additional test was conducted to assess a newly developed sensor, The Infra-Red Traffic Logger (TRITL), for its ability to collect axle-based vehicle classification data. Test method and results are included in the project’s final report.