How does a dirty windshield affect driving at night?

How does a dirty windshield affect driving at night?

• A. Lights from oncoming traffic can hit it and create a glare
• B. It causes bugs to stick more easily to the windshield and block your view
• C. Both A and B
• D. It helps deflect the light of oncoming traffic so it doesn't blind you

Answer: (A)

At night, the biggest danger from a dirty windshield is glare from oncoming headlights. A film of dirt or smeared moisture on the glass scatters bright light, creating halos and a washed-out field of view that makes it hard to judge distances, see pedestrians, or read signs. This reduced visibility can significantly slow your reaction time and increase the risk of a crash. Bugs sticking to the windshield and minor obstructions can contribute to visibility issues, but they’re not the primary or most consistent hazard at night. And dirt doesn’t “deflect” light to help you; it tends to diffuse and scatter it, which worsens glare rather than improves visibility.

At night, the biggest danger from a dirty windshield is glare from oncoming headlights. A film of dirt or smeared moisture on the glass scatters bright light, creating halos and a washed-out field of view that makes it hard to judge distances, see pedestrians, or read signs. This reduced visibility can significantly slow your reaction time and increase the risk of a crash.

Bugs sticking to the windshield and minor obstructions can contribute to visibility issues, but they’re not the primary or most consistent hazard at night. And dirt doesn’t “deflect” light to help you; it tends to diffuse and scatter it, which worsens glare rather than improves visibility.