I went to Yosemite with a photo group. We stopped at the first waterfall (Bridalveil falls) to meet up and plan the day. The spots closest to the waterfall were covered in ice. I decided not to park there, but others didn't want to walk the extra 30 feet to the trailhead and they parked in those spots. When we got back, the heat from the car engines melted the ice, and they had to wade through 10+ inches of puddle to get in their cars.