As of 2010, the United States does not require vehicles to be equipped with daytime running lights. However, some states do require drivers to turn their lights on during the day in poor weather conditions.
Purpose
The purpose of daytime running light laws is to ensure the safety of all vehicles on the road, especially when driving conditions are poor. The use of daytime running lights allows all vehicles to be seen. Many car companies in the United States, such as General Motors, install daytime running lights on all of their vehicles.
Motorcycles
As of 2010, federal law does not require motorcycle riders to use daytime running lights. However, states do have the ability to create their own laws regarding their use. For example, California requires all motorcycles built after 1977 to be equipped with daytime running lights.
Outside the United States
According to Business Week, Finland became the first country to mandate all vehicles have daytime running lights during winter weather. This law was passed in 1972. In Canada, daytime running lights are only required on vehicles manufactured after Dec. 1, 1989. Other areas of the world, including Denmark, Iceland and Hungary, also require daytime running lights.