Daughter and Hercules got their driveway sealed the other day. (I got mine done, too.) One hour until it dried enough to walk on, three hours until the cars could sit on it. Not hot tar - it went on cold. I frankly don't know what it was.
Nobody told the Nugget about not walking on it. She came running across the lawn, and got five barefoot steps onto the fresh driveway before her Mommy caught her.
Her feet were solid black. I suggested they just let it dry, they could save on shoes....
It washed off with soap and water and a little sugar for scrubbing.