My impression from the first viewing was that tyre barriers and gravel traps would have made little difference. The car basically bounced over the fence, you would have needed tyres 20 deep to stop that, otherwise it just would have jumped them. And gravel traps do almost nothing to slow a car that's rolling. Once the car started sliding on its roof and rolling, the only way to stop it was with a 10-metre-high catch fence. Nothing else would have made a difference.