In adverse weather such as snow, fog, ice, or rain, by how much should you reduce your speed?

• A. 5 to 10 percent
• B. 10 to 20 percent
• C. 20 to 50 percent
• D. 60 to 70 percent

Answer: (C)

Adverse weather reduces traction and visibility, so you must slow enough to maintain control and give yourself time to react and stop. A practical guideline is to reduce your normal speed by about twenty to fifty percent. That range covers conditions from light rain or fog to heavy snow or icy pavement, with you using the lower end when weather is only mildly worse and the higher end when conditions are more severe. Smaller reductions often aren’t enough to keep you safe on slick surfaces, while drastic cuts can create hazards because other drivers aren’t moving that slowly. Always pair the speed reduction with a longer following distance to maintain a safe stopping space.