An unmanned integrated RES 12 integrates all of its components except the reflector 22 into a single console 30 that is positioned at the side of a road and has a CPU 36 that controls calibration, verification and data gathering. The RES's source 32 and receiver 34 are preferably stacked one on top of the other such that the IR beam 24 traverses a low and high path as it crosses the road 14. This allows the RES to detect both low and high ground clearance vehicles. To maintain the vehicle processing and identification throughput, the speed sensor 54 and ALPR 48,50 detect the passing vehicles at steep angles, approximately 20 to 35 degrees. In a preferred system, a manned control center 16 communicates with a large number of the unmanned integrated RES to download emissions data, perform remote diagnostics, and, if necessary, dispatch a technician to perform maintenance on a particular RES.