The VSC was tested over the course of the final three races of the season, during parts of free practice sessions. The system was evolved taking into account drivers' feedback and was officially introduced for the season following ratification by the World Motor Sport Council (WMSC). The VSC was officially used for the first time – and for a brief period prior to the deployment of the actual safety car – at the 2015 Monaco Grand Prix, following a 30G crash involving Max Verstappen. The system saw its first extended deployment at the 2015 British Grand Prix after Carlos Sainz Jr.'s power unit failed at Club Corner of the Silverstone Circuit. All drivers must keep their delta times positive at this point.