Running lights are the lights on the front end of a vehicle that automatically turn on when the vehicle is started and stay on as long as the engine is running. They do not operate at the same brightness level as headlights or high beams. Also referred to as daytime running lights or DRLs, they were first widely introduced on several makes and models of vehicles in the United States in the early 1990s. Though the United States currently has no law mandating these lights, many countries, including Canada and several European countries, have laws regarding their use.
Though the design and use of running lights has been the center of controversy, studies performed by the Insurance Institute for Highway Safety and similar institutions have found that their use is effective at preventing daytime, head-on collisions by increasing the visibility of vehicles. However, many people argue that they increase fuel spending and creates the potential to neglect the manual operation of vehicle lights at night.
Increased fuel spending, while a legitimate concern, is actually minimal with an increased cost average of only a few US Dollars annually. However, many drivers of vehicles that have these lights forget to manually turn on their headlights at night. Because they only operate from the front of the car, not the rear, forgetfulness at night can be a dangerous problem.
Because of increased safety, almost every make and model of passenger car, pickup truck, van, and SUV now comes standard with daytime running lights. General Motors, as well as other retailers, offers retrofit kits for older vehicles that do not have them. While DRLs are designed to be automatic, drivers must still assume responsibility for turning on their lights when driving at night and in weather that creates poor visibility.