Drivers in and around Milwaukee were warned to expect dangerously limited visibility on Tuesday, October 20, after the National Weather Service issued a dense fog advisory across parts of south-eastern Wisconsin.
The advisory covered Milwaukee and surrounding counties including Waukesha, Racine, Kenosha, Ozaukee, Washington, Sheboygan, Fond du Lac, Dodge, Jefferson and Walworth. Visibility was expected to fall to a quarter of a mile or less in the thickest fog, creating hazardous conditions during the morning commute.
Which headlights should drivers use in dense fog?
Motorists were advised to use dipped-beam headlights rather than full beams. High-beam headlights project light further into the fog, where it reflects off tiny water droplets and can create glare directly in front of the driver.
That reflected light can make the fog appear brighter while making road markings, vehicles and hazards harder to distinguish. Fog lights, where fitted, are mounted lower on the vehicle and are designed to illuminate the road surface and lane markings more effectively.
The National Weather Service also recommends using low-beam headlights in fog during daylight as well as at night, helping other road users see the vehicle and ensuring its rear lights are illuminated.
Drivers should reduce their speed and leave considerably more space between vehicles, as visibility can deteriorate rapidly and stopping distances become harder to judge. Road lines and markings can help motorists remain in their lane, but lane changes and overtaking should be avoided unless absolutely necessary.
In areas where visibility becomes almost non-existent, the safest option may be to pull into a suitable car park or other safe location and wait for conditions to improve. Anyone forced to stop at the roadside should move as far from traffic as possible and use hazard warning lights.
Fog forms close to the ground when water vapour condenses into tiny droplets in the air. Unlike clouds, which can develop at different heights, fog remains at or near the surface, where it can quickly obstruct drivers’ view.
The Milwaukee-area advisory was extended during the morning and remained in effect until 10am local time on Tuesday. Forecast information should be checked before travelling, particularly where further patches of fog are expected.
