man vs locked car
May 3, 2012 6:01 AM   Subscribe

What laws or rules govern automobile door locks in the United States?

This question is spurred by the report from a friend of mine that a certain new VW has an unusual door design: there's no frame around the window when the door is open. When the door is closed, the top of the window is kept captive in a channel that is built into the car frame. When the door handle is operated, the window is (electrically, one assumes) lowered so that the window clears the channel before the door will actually open.

It seems like this design will prevent someone inside the car from exiting if the car's electrical system is not operating, and this seems like a real safety problem of the sort you'd hope regulation would prohibit if the common sense and review practices of car manufacturers wouldn't. So what rules are there about car door locks?

This question isn't really about the specific car I'm describing above, it's about what regulations are. But if you know what car I'm talking about and can clarify my description, that'd be great too.
posted by jepler to Travel & Transportation (20 answers total)
I don't know about laws or regulations, but I know the Subaru Legacy I had in the mid-90s had this same design. I also know that the door opened just fine when I had a dead battery once or twice, but I admit I'm not sure how.
posted by Rock Steady at 6:06 AM on May 3, 2012

Are you sure the window actually goes up into the roof? I used to know a mid-60's Buick that didn't have a frame around the window: when the door was closed, the sides and top of the window merely sealed against the rubber gasket.
posted by easily confused at 6:12 AM on May 3, 2012

US Department of Transportation. The National Highway Traffic Safety Administration has a legislative mandate under Title 49 of the United States Code, Chapter 301, Motor Vehicle Safety, to issue Federal Motor Vehicle Safety Standards (FMVSS) and Regulations. Manufacturers of motor vehicles and their equipment items must conform to these regs and certify compliance.
posted by crush-onastick at 6:13 AM on May 3, 2012

The window just goes up a little bit to help it seal better. It wouldn't stop you from opening it.
posted by ftm at 6:13 AM on May 3, 2012 [2 favorites]

Well, here's the NHTSA standard on doors and door locks. It seems to be mostly concerned with doors staying closed (in a crash) than opening.

I suspect that you could get that door open without electricity, though - either the window can be lowered mechanically (by some action with the door handle) or you can open the door even with the window open.
posted by mskyle at 6:16 AM on May 3, 2012

[premature posting!]

You'd find specific rules about door locks Code of Federal Regulations. CFRs are voluminous and ever-changing and generally available on-line or otherwise through the Government Printing Office. A quick search turned up a CFR regarding door locks from October 2000, but there are undoubtedly more recent ones.
posted by crush-onastick at 6:17 AM on May 3, 2012

(oh cool! I did not know Cornell had CFRs online, too)
posted by crush-onastick at 6:17 AM on May 3, 2012

My '97 Subaru had windows like that. The top channel is just a beefy strip of foam that rocks outward and covers the top line of glass when the door is closed (or you roll up the window). It worked perfectly. Maybe the VW has some sort of fancy-pants electrical system but the simple machine of a foam rubber lever with a bit of sway sure did the trick on my Sooby.
posted by dirtdirt at 6:25 AM on May 3, 2012

Having no frame around the window isn't really that weird; "hardtop" cars going back to the 40s had frameless windows. The bit about the electric window motor bumping the window up to better seal is new, though.

I doubt it goes up far enough to get in the way if the door is being opened in an emergency. A reasonably strong person can peel back the window frame in a framed door far enough to get fingers in.
posted by notsnot at 6:29 AM on May 3, 2012 [1 favorite]

I've had several cars that didn't have a top frame around the window and that do the electrical motor trick when you open or shut them. The side effect if the electric motor fails is that the window doesn't seal properly when you shut the door and wind noise enters the passenger compartment. You can still open the door, the weatherstripping that the window seats into isn't rigid enough to prevent the door from opening or closing. Having that fail on new Beetles is a relatively common complaint
posted by Lame_username at 7:03 AM on May 3, 2012 [1 favorite]

I wonder if it's not a fail-safe design, such that if the electrical system loses power it mechanically reverts to the lowered position.
posted by drlith at 7:08 AM on May 3, 2012 [2 favorites]

I literally just five minutes ago gave my car ('08 Mustang, which has these kinds of windows) back to the garage that replaced a dead battery, because the battery died again. In normal operation, the window goes down just a skoonch when you open the door, then goes back up when you close it. After the battery died (and it was tooootally dead), the window didn't go down that skoonch when the door opened (I did look, because I've idly wondered this very question ever since I got the car), but the seal didn't prevent it from opening or closing at all.
posted by Etrigan at 7:46 AM on May 3, 2012

I was going to say the Mustang, too. The older ones (a '92, definitely, from personal knowledge) didn't bother moving the window up and down when the door opens, and the doors are still fine. I hadn't thought about getting a better seal that way, I always thought it was just to remove a bit of stress on the window in case you slam the door excessively... Either way, it's definitely an optional feature rather than a necessity.
posted by anaelith at 7:49 AM on May 3, 2012

This is how my '02 Mini worked as well - it's not all that uncommon and the window isn't 'captured' by any sort of channel - it's just being pushed up to make a tighter seal.
posted by pupdog at 8:00 AM on May 3, 2012

This question is spurred by the report from a friend of mine that a certain new VW has an unusual door design: there's no frame around the window when the door is open.

This is a pretty common design and has been around for years. The window will not be held inside steel of the roof, but within a rubber seal anyway. The window will drop when you pop the handle, but this is just to reduce wear on the rubber seal - the structure and seal above the door does not lock the door or window in place at all.

There is a huge raft of regulations for door locks (which is not the same as your question as the window is not part of the door lock) that govern resistance to bursting open in accidents while maintaining the possibility of being opened. It is a BIG deal that doors must be openable in an accident, so this design will not at all compromise that.
posted by Brockles at 8:52 AM on May 3, 2012

The door will open. It'll just feel weird.

I had a car that did this too. After sleet or freezing rain, a layer of ice at the bottom of the window prevented the glass from dropping when I opened the door. I got into and out of the car just fine. There was just more of a clunk than usual.
posted by hwyengr at 9:41 AM on May 3, 2012

The Ford Focus CC does this, becuase it is a hard-top convertible. Actuating the door handle (interior or exterior) mechanically releases the door, as any other car, and the window electrically drops a short distance. The window rises when the door is shut fully.

The manual says nothing about what happens where there is no electrical power supplied to the vehicle, but as the door is released, I imagine that you could push the door open even if the window has not dropped although this may result in damage. The window has some play to it, so there may be enough give to allow you to open the doors in an emergency. This sounds like what hwyengr is describing. I'm not about to test it just in case I end up needing to buy new glass.
posted by NordyneDefenceDynamics at 2:37 PM on May 3, 2012

The Mercedes CLK does this too. It also doesn't have a B pillar. The window doesn't go into the frame to prevent the door from opening. It just moves to provide a better seal.

The window doesn't lower when the door is opened.
posted by wongcorgi at 5:20 PM on May 3, 2012

My friend says that the car that inspired my question is a 2012 VW CC, and insists that the window is not merely pressed against a rubber seal (like my '99 Subaru Legacy), but is captured in a channel in the frame. I still haven't seen the car for myself. I did find this video showing the difficulty of opening the car door when there is ice on the window [youtube] but it doesn't really show how far up the window goes when it's raised.

I checked a few "best answers" where there were links to actual federal regulations, none of which seem to require the "fail safe" doors that we all seem to imagine should be required.
posted by jepler at 10:03 AM on May 4, 2012

If your friend is really concerned about getting trapped in the car, disconnect the battery and see if the door opens without the window moving.
posted by hwyengr at 6:08 PM on May 4, 2012 [1 favorite]

« Older Do I list a consulting agency on my resume?   |   where do I go for help for knee pain? Newer »
This thread is closed to new comments.