In fact studies have shown that drivers are attracted to the three lamp array as it looks different than any other vehicle. On top of that, drivers are able to better estimate the oncoming cyclist’s rate of approach. These truths were the result of several tests.
Trains went to a three lamp system, replacing their single lamp that utilized a motorized reflector to cause the lamp to shine in a circular motion. The three-lamp system reduced the number of train / vehicle (or pedestrian) collisions.
Might be wise for those not already having a primary lamp and two auxiliary driving lights to consider adding an LED light duo. Some cyclists have put them down low on the forks. LED’s are popular because of their minimal drain on the battery/charging system. (New Source AMA) - Adam 12