In Formula 1 next season, the intention is that after a safety car period, we are going to have a full standing restart.
The FIA has said that it doesn't consider grid starts to be any more dangerous than what happens now with the cars getting back underway in single file behind the safety car. But I believe they need to look at the starts of the recent British and German Grands Prix for evidence that this is not so.
Any time that 22 high-performance racing cars are in as close a proximity as they are on the grid, it can always lead to potential disaster. If there's any doubt of that, perhaps have a word with Felipe Massa, whose world was turned upside-down at the start at Hockenheim.