There was some calculations done last year that showed a carbon fibre wheel and low profile tyre combination would weigh half the current solution. Half the weight, half the energy.
Most sensible post on this thread. In the last 20 years 50% of the fatalities in F1 have been marshalls not drivers. And the two driver fatalities were from accidents that would definitely not be fatal now. Yet the safety of marshalls and spectators has improved significantly less than driver safety.
The fronal roll hoop and canopy solutions might protect drivers but would do nothing to prevent the much more likely scenario of bystander injury. Reducing the weight of the wheels and tyres should reduce the hazard significantly, especially if it meant the wheel tethers would actually become capable of retaining the wheels in the vicinity of the cars.
On the issue of driver safety I don't tend towards either extreme in the debate - those who think any measure that improves driver safety has to be accepted regardless need to explain why they don't simply favour banning motorsport, which would eliminate the risk straight away. But those who say well, it's always been dangerous and it always will be who cares, need to remember that with that attitude we'd still be losing drivers and spectators and marshalls at the rate we were in the killer years, and that would be no good either.
So I think the proposals should be looked at, we need to ask what the effect on safety would be, and we also should listen to those who argue it would harm F1 in a sporting sense, because if we're not bothered about the sport and our enjoyment of it, then the safest thing would be to pack up and go home.
I recall somebody, I think it was Pat Symmonds, saying of the forward roll hoop that although one might think it would obscure the driver's view, it would end up being like the bulkhead in a road car - you would just get used to it. Problem is, if you pay attention to what happens when you approach a junction in your road car, sometimes the bulkhead does get in the way and so, unconsciously, you move your head forward or to the side so you can see around it. That's what the chap in that 70s single seater pictured earlier in this thread probably did, too, to see around his roll cage. Except F1 drivers can't do that now. If you put that roll hoop in front of an F1 driver's head he'll have two massive blind spots. I also note that the crash tests they've done have been with wheels that dont have suspension peices attached to them and pointing at the driver at the point of impact. That's not the scenario that faced Henry Surtees. So that's a disadvantage of the roll hoop as compared to the canopy.
Apparently the FIA is not favouring the canopy bacause, as things stand, it can't be made strong enough to give the sought after protection against intrusion and, whatever people think, it's not going to make cockpit evacuation any easier, is it? So I'd assume these ideas will need to be developed further before we'll see either of them used.