Evaluation of lane-by-lane vehicle detection for actuated controllers serving multilane approaches

A comparison was conducted of traditional vehicle detection, in which all lanes on an approach are connected to an actuated controller through one amplifier card and input, and lane-by-lane detection, in which each lane is interfaced with the controller through separate amplifier cards and inputs. Both detection strategies were evaluated with various extension time values on the same traffic stream. A total of 430 h of data from two separate approaches was evaluated on an hour-by-hour basis. During certain time periods, lane-by-lane detection provided up to a 13% increase in efficiency. For all 930 h of observations, the median increase in efficiency was 5.2% on an approach with 51-ft-long detection zones and 3.5% on an approach with 38-ft-long detection zones. This increased efficiency corresponds to time that could be allocated to other movements or used to reduce the cycle length. The largest improvements associated with lane-by-lane detection occurred during periods with moderate volume-to-capacity ratios, with smaller benefits observed during periods of heavy or light traffic.