A green-white-checker (GWC) is a NASCAR-specific rule for ensuring races finish under green flag racing conditions rather than ending under caution.

Mercedes-Benz's head of motorsport Toto Wolff says the "unacceptable" collision between Nico Rosberg and Lewis Hamilton at Spa-Francorchamps "cannot - and will not - happen again".Wolff said the accident, which occurred at Les Combes on the second lap, was a clear transgression of the fundamental rules Mercedes have laid down...