The FIA have pre-empted this post by choosing the halo design but I was going to write something about the plans for increasing cockpit safety anyway.
Your fears are formed by what you see.
The two most recent serious F1 accidents have featured something hitting the driver’s head while they’re seated in their vehicle. Understandably, this has led to calls for fully enclosed cockpits to be used in F1. The first F1 accident I remember was Gerhard Berger’s 1989 crash at Imola. Which I swear is where my fear of burning to death comes from. Now, that ended happily, or at least only with minor injuries, but the main reason I don’t like the idea of having fighter jet-style canopies is what happens if they fail to release.
The other problem with a full canopy is how it would be cleaned as it got dirty. If the driver is fully sealed, he can’t just rip off a tear-off strip the way you can with helmets. Sure, the mechanics could do it during a pit stop. But what if it got dirty in-between times, or if the car in front sprayed oil all over the canopy because of a mechanical failure?
I suspect these problems, or something similar, are the reason why the FIA and the teams haven’t even tried anything like a full, sealed canopy.
With a “shield”, there aren’t the same problems. The driver can get out, and I presume tear-offs can be made for them. On the other hand, objects can still bounce off and in, and something could go over and in to the cockpit. I don’t think that you’re ever going to be able to make any motorsport 100% safe, but I think the shield is probably the best option. It mixes increasing safety without introducing different risks or just leaving things as is of the solutions so far put forward.
I don’t get what the halo is supposed to do. I’m sure I’m missing something, and I’m sure someone with more engineering know-how can explain it to me. It seems to offer very little extra protection while reducing the driver’s field of vision. I don’t think the central column visibility issues will be as bad as it looks (see also how quickly you can get used to seeing through mesh in a fencing mask). However, I’ve no idea how it’s supposed to prevent objects entering the cockpit. It seems to only be capable of preventing things if they’re on a trajectory that crosses over the halo pillars and bars.
The FIA have gone with the halo over the shield. I’m sure they have their reasons. I’m sure they are good reasons. It would be nice to know what those reasons are because from the outside, it looks like a ridiculous decision.