Daytime Running Lights are not sufficient in poor light. As the winter days get shorter, frosty and foggy conditions are occurring more, meaning visibility on the road is frequently reduced. When driving, it is important to use appropriate lights, not only so you can see the road ahead, but also so other road users can see your vehicle (both from the front and the rear).
Many vehicles on the road now utilise Daytime Running Lights (DRL), as these have been mandatory in newly manufactured vehicles since 2011. DRL are automatically activated when the engine of the vehicle is turned on, and they provide enough light to ensure that vehicles are visible from the front during the daytime (they are not as bright as dipped headlights). DRL have a positive road safety effect - research has shown that they are likely to reduce daytime collisions, as they allow the increased visibility of oncoming vehicles.
However, RoSPA have had several enquiries about, and have noticed ourselves, the fact that many drivers are using DRL in conditions of poor visibility, and not switching to dipped headlights or fog lights. It is likely that these drivers either think DRL are sufficient in poor visibility, or they think DRL illuminates the vehicle from the front and rear, when it in fact they only provide visibility to the front of the vehicle – they do not illuminate the rear of the vehicle.
Relying on DRL only in conditions of poor visibility is a serious issue and creates a crash risk, not only for the driver but for the other road users around them. Drivers must use the appropriate level of lighting for the conditions. The Highway Code rule for this is as follows:
Rule 226: You MUST use headlights when visibility is seriously reduced, generally when you cannot see for more than 100 metres (328 feet). You may also use front or rear fog lights but you MUST switch them off when visibility improves.
RoSPA wants drivers to be aware that DRL are not sufficient in conditions of reduced visibility. Not only are they not bright enough, but they do not provide light to both ends of the vehicle. It is especially important to be aware of this during winter, and when travelling on high-speed roads/motorways, where good visibility is even more crucial.
Holly Moore, road safety support officer
Posted: 12/23/2019 10:16:16 AM