SRF, in association with the Minnesota Department of Transportation, conducted a series of field tests of non-intrusive vehicle detection technologies to determine their feasibility as alternatives to conventional roadway-based traffic counting and detection technologies. SRF evaluated the extent to which non-intrusive technologies (NIT) offer advantages in safety, data collection, data quality, and cost-effectiveness.
Non-intrusive technologies are able to minimize traffic disruptions, improve safety for traffic data collection personnel, and provide a cost-effective alternative to other methods of monitoring traffic. The non-intrusive technologies evaluated included microwave, magnetic, laser, sonic, ultrasonic, infrared, and video image detection. SRF tested sensors under a variety of mounting configurations over the course of several project phases. We also designed, fabricated, and field-tested a portable non-intrusive traffic (PNIT) detection system that can be quickly attached to existing streetlight poles and signposts along freeways and arterials – a sidefire sensor monitors multiple lanes of traffic, offering a self-contained and completely portable alternative to road tube detection.
The final reports for NIT studies can be viewed at:
The PNIT study can be viewed at: