This is the third and final report of the evaluation of the Sensys wireless vehicle detection system at a
signalized intersection and a railroad grade crossing. It presents the system performance after one year of its
initial installation, and when additional off-center sensors were installed at the stop bar zones of the signalized
intersection. Results from the signalized intersection showed no significant changes one year after the system
was in use, except for a decrease in the frequency of false calls due to vehicles in adjacent lanes (from a range
of 5.6%-7.6%, to a range of 0.8%-2.4%). At the stop bar zones, multiple calls generated by a single vehicle
remained similar (between 7% and 10.2%), and no missed, stuck-on, or dropped calls were found. Also, the
detection performance at the advance zones did not change. Missed vehicles ranged between 0.6% and 6.1%,
most of which were traveling between lanes, and false calls were lower than 2%. At the railroad grade crossing,
the performance of the Sensys system after one year did not show significant changes. Stuck-on calls due to
trains were rare and occurred at a rate of about one occurrence for every 150 trains. False calls in the left-turn
lane due to vehicles in the opposite direction remained high (more than 30%, caused by trucks and smaller
vehicles), and missed calls were lower than 1%. The installation of sensors off-center relative to the loop
detectors at the stop bar zones of the signalized intersection (close to the leading edge of the loops), resulted
in lower number of multiple calls from a single vehicle (from 7%-10.2% down to 2%-3.3%). However, it did not
improve on the frequency of false calls due to vehicles in the adjacent lanes.Illinois Department of Transportation ICT R27-58published or submitted for publicationnot peer reviewe
