Should I leave daytime running lights on?
Yes. In most situations, keeping daytime running lights (DRLs) on during daylight improves visibility for other road users and pedestrians, with minimal downside in modern vehicles. Always follow local laws and your vehicle’s manual.
Daytime running lights are low‑intensity front lights that illuminate automatically when the engine is running, separate from full headlights and parking lights. They are designed to boost daytime conspicuity, but their effectiveness varies with conditions and regional rules. This article explains when to keep DRLs on, when to switch to other lighting, and how regulations differ around the world.
Benefits of leaving DRLs on during the day
Understanding the safety advantages can help you decide whether to keep DRLs active during typical daytime driving.
- Increased conspicuity: DRLs make your vehicle more visible to other drivers and pedestrians during daylight.
- Potential crash reduction: research indicates daytime visibility improvements can lower certain types of daytime crashes, though results vary by location and driving conditions.
- Minimal energy impact: modern DRLs use efficient lighting (often LEDs) and have a negligible effect on fuel economy or vehicle battery life when the engine is running.
Overall, DRLs are a safety feature meant to enhance daytime visibility without imposing significant drawbacks for most drivers.
When DRLs might be less ideal or not required
There are scenarios where relying solely on DRLs is not the best choice for safety or compliance.
- Fog, heavy rain, or low visibility: DRLs are not a substitute for low-beam headlights or fog lights; use appropriate headlights to improve scene illumination and reduce glare for others.
- Glare for oncoming drivers: in some conditions, DRLs can contribute to glare; switching to low beams can improve comfort and safety for others.
- Battery or vehicle settings: on some older or certain model configurations, DRLs may stay on even with the engine off or in accessory mode, potentially draining the battery if used improperly; consult your manual for specifics.
In challenging visibility conditions, treat DRLs as a daytime safety aid, not a replacement for proper lighting.
Regional rules and recommendations
Lighting regulations vary by country and region, which can influence whether you should keep DRLs on and how they operate.
- European Union and many other regions: DRLs are mandatory for new passenger cars in numerous markets (EU has required them since around 2011).
- Canada: DRLs are required on most new vehicles, reinforcing daytime visibility targets.
- United States: There is no federal DRL mandate; many vehicles include DRLs as standard or optional features, but rule compliance varies by state and vehicle.
- Other regions: DRLs are common or legally encouraged in many countries; always check local regulations and your vehicle’s manual.
Knowing the rules helps ensure you use the right lighting and stay compliant with local laws while driving.
Practical tips for everyday use
These practical guidelines can help you optimize DRL use in daily driving scenarios.
- Keep DRLs on during daytime driving unless your local laws require you to switch them off or your vehicle’s settings specify otherwise.
- In fog, rain, or other poor-visibility conditions, switch to low-beam headlights (and use fog lights if equipped) as appropriate.
- If your car supports automatic headlights/DRLs, enable that mode to ensure proper lighting under varying conditions.
- Be mindful of glare: if oncoming drivers appear uncomfortable or if you notice excessive glare, adjust by using low beams when needed.
DRLs are a daytime safety aid that works best when paired with proper headlights in poor visibility and when compliant with local regulations.
Summary
For most drivers, leaving DRLs on during the day is advisable, as it improves visibility with minimal drawbacks. Always comply with local regulations and your vehicle’s settings, and switch to low beams in fog, heavy rain, or low-visibility situations. Refer to your owner’s manual to understand how your DRLs operate and how to adjust them if required.
