Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Is a glass roof a concern for rear passengers when hitting a speed bump too fast?

This site may earn commission on affiliate links.

NeverFollow

Active Member
Aug 9, 2010
1,281
814
As a back seat passenger, I once experienced hitting the roof of a car while the driver didn’t slow down enough when passing above a speed bump. May be I was surprised and may be the fact to be sitting on the back made the bump more brutal. However, for a long time, my head and my back were hurting me.

So looking at the description of the Model 3, for which a glass panel replaces the metal roof , I am wondering if there would be potentially a more serious risk of getting an head concussion when hitting a speed bump too fast in the case of a glass roof versus a metal roof with a thin insulation layer?

red_1-jpg.169888


img_6998-png.169928
 
Last edited:
  • Disagree
Reactions: loganthefirst
As long as your passengers are wearing their seatbelts and you are slowing down on your approach of the speed bump, I don't think you'll have an issue. I definitely agree though that hitting hardened glass is definitely going to hurt more than a soft compression liner that you find in most vehicles.
 
I've had no problem in three years. I don't think that there is enough difference between glass and the minimal padding in other cars to make any real difference.
 
I knew someone once that had a corvette. For those of you not familiar with the options, you can get one with a standard roof, a glass roof, or a combination of the two. The standard roof has the traditional headliner. My friend had the glass roof. One day, while sitting at a light, someone rear ended him, hard. The impact was such that it lifted the back of the car and he was thrown up into the glass roof. It did not break, but the impact caused severe head trauma, and he had to have brain surgery. He was a big guy, over 6 feet, and he was wearing a seat belt. His mother was in the car (she is also pretty tall), but did not experience any injury.

I know this was a very unusual accident/injury, but there are cases where a glass roof could be dangerous. Traditional roofs have padding. Please don't anyone read this as me advocating against offering the option. Hell, if we really want to be safe, ban the wheel completely. Just take it as an example of a place where it would not be that safe.
 
Hitting a glass roof probably is more dangerous in an extreme case (see above for the unfortunate Corvette story) but not much in nearly any other event. I'm 6'3" and thump car ceilings all the time. I think I'm better off if I don't have to crane my neck sideways to "fit" in the back seat. Perhaps there's a greater chance of a concussion??

I for one am absolutely sold on the fixed glass roof since the open view/ feeling reminds me of my first car, a Triumph TR-4.
 
The faster you hit the speed bump, the less significant the impact will be re the vehicle's frame of reference. Certainly wrt a well suspended and damped Tesla.

Even with solar-blocked glass with 0.32 transmissivity, I'd not want a glass roof if I lived at high altitude below the 45th parallel. But perhaps I worry too much.
--
 
I knew someone once that had a corvette. For those of you not familiar with the options, you can get one with a standard roof, a glass roof, or a combination of the two. The standard roof has the traditional headliner. My friend had the glass roof. One day, while sitting at a light, someone rear ended him, hard. The impact was such that it lifted the back of the car and he was thrown up into the glass roof. It did not break, but the impact caused severe head trauma, and he had to have brain surgery. He was a big guy, over 6 feet, and he was wearing a seat belt. His mother was in the car (she is also pretty tall), but did not experience any injury.

I know this was a very unusual accident/injury, but there are cases where a glass roof could be dangerous. Traditional roofs have padding. Please don't anyone read this as me advocating against offering the option. Hell, if we really want to be safe, ban the wheel completely. Just take it as an example of a place where it would not be that safe.

I doubt that having metal roof with a liner would have helped in his situation.
 
I knew someone once that had a corvette. For those of you not familiar with the options, you can get one with a standard roof, a glass roof, or a combination of the two. The standard roof has the traditional headliner. My friend had the glass roof. One day, while sitting at a light, someone rear ended him, hard. The impact was such that it lifted the back of the car and he was thrown up into the glass roof. It did not break, but the impact caused severe head trauma, and he had to have brain surgery. He was a big guy, over 6 feet, and he was wearing a seat belt. His mother was in the car (she is also pretty tall), but did not experience any injury.

Your assumption is that he wouldn't have been injured as badly if that portion of the roof been metal, with a very thin headliners as cushion. You'd have to provide an example of this to be able to draw any conclusions about the two materials.
 
  • Informative
Reactions: hoang51
Your assumption is that he wouldn't have been injured as badly if that portion of the roof been metal, with a very thin headliners as cushion. You'd have to provide an example of this to be able to draw any conclusions about the two materials.

What I took from that story about the Corvette crash was that someone earlier said to wear a seat belt for the rear passengers:

Wear a seatbelt.

Seriously. I haven't had to wear a helmet in the back of a vehicle since I left the army. No seatbelts in the back of of an APC.

In that case, the Corvette story indicated that a seat belt would not have prevented vertical displacement:

I knew someone once that had a corvette. ... The impact was such that it lifted the back of the car and he was thrown up into the glass roof. ... He was a big guy, over 6 feet, and he was wearing a seat belt. ...
 
A five point seatbelt would probably be the best protection but they never caught on, except for race cars.

I am a single engine plane pilot. The headroom in a Cessna is more than a car. In severe turbulence once I hit my head. I could never figure out how because I was belted in, tight, with a lap belt and shoulder harness (3 point, not 5). Luckily I did not lose consciousness. The materials and the seats have give and the seat belts are just not designed to prevent vertical movement.
 
A five point seatbelt would probably be the best protection but they never caught on, except for race cars.

I am a single engine plane pilot. The headroom in a Cessna is more than a car. In severe turbulence once I hit my head. I could never figure out how because I was belted in, tight, with a lap belt and shoulder harness (3 point, not 5). Luckily I did not lose consciousness. The materials and the seats have give and the seat belts are just not designed to prevent vertical movement.
Often the inertia reels are gummed up and don't work fast enough, combined with the fact almost no one removes enough slack from the lap belt portion after connecting the belt buckle.

Both just take a bit of effort to remedie.