On vehicles equipped with DRL, the light is automatically switched on when the engine is started. When it is dark the driver has to switch on the driving lights manually. In this case the DRL goes off automatically. Because of this they are expected to increase road safety as they substantially raise the visibility of motor vehicles for other road users.

They also have a low energy consumption rate compared with existing "dipped-beam" head lights, offering environmental benefits. The energy consumption is approximately 25-30% of the consumption of a standard driving light. And when a LED (Light Emitting Diode) is used for the DRL, the energy consumption is further reduced to only 10%.

European Commission Vice President Antonio Tajani, responsible for industry and entrepreneurship said: 'Daytime running lights will make an important contribution to our goal of reducing casualties on European roads. This is also good news for environment protection as the lower energy consumption rates will reduce CO2 emissions compared to normal lights.'

According to the European Commission, road users, including pedestrians, cyclists and motorcyclists can detect vehicles equipped with DRL more clearly and quicker than those equipped with dipped beam head lights.

The European Commission said: 'Directive 2008/89/EC on the obligatory fitting of vehicles with DLR, which comes into force today, will greatly contribute to the safety of Europe's roads. It will harmonise national requirements on the mandatory fitting of DRL to new types of vehicles which up to now have been varying greatly between EU Member States.'

Daytime lights are currently mandatory for driving in countries including Poland, Denmark, Finland, Sweden, Iceland, Slovakia and Norway.