From a Milwaukee news report today:
"Washington County Sheriff’s officials say the southbound lanes of US 41 north of Sherman Road in the Town of Polk suffered a lightning strike as storms rolled through on Thursday, August 22nd.
The call was taken by Sheriff’s dispatchers at 11:18 AM. When deputies arrived to the area, they found an approximately 18 inch deep, 3 feet long hole blasted from the asphalt road."
Lightening doesn't always strike the highest object, obviously. A dump truck was also struck scattering some its load about the area.