Is a locked car door any safer in terms of opening?

I’m sure that subject line isn’t the best for the question, so I’ll try to save it here.

I got into a discussion with a friend regarding locking a car door. He insists that I lock my door when we get into the car. A good idea, but I don’t think for the reason he believes it’s a good idea.

He says: Locking a car door not only disllows the outer handle to function, but it also sets what would be equal to a “deadbolt” securing the door further.

I say: Locking the car door simply disallows the outer handle to function.

Who is correct? (Generally I mean - I’m sure car door locks differ a great deal. BTW - this is a 1986 Nissan Maxima if that helps)

You are right. Your friend is wrong.

For a more detailed answer, you can do a search on ‘car door’. I tried to do it myself, but my browser is just hanging.

it would depend on what you want by safer. you want it so that you can’t open the door from the inside with it locked, or to make it harder for someone to open in from the outside. I’ll restrict myself to Fords since that’s all I’ve ever owned.

Newer Mustangs, at least 86 on, just open the door and it unlocks itself, not good if you want to keep your suicidal buddy from jumping. Older Mustangs, at least my 67, you have to unlock it yourself. My 96 Escort you also have to unlock it yourself.

I don’t lock my doors at all, I don’t see a reason too. well I guess I do sometimes when I’m giong through a bad neighbor hood, but that’s about it.

My wife and I talked recently about this very thing. I was taught in high school drivers education to lock the doors because it reduces the risk of the door opening during an accident. My wife’s mother used to drive an ambulance and she taught my wife not to lock the door because it made it more difficult for emergency personnel to get to you if you can’t unlock it for them. We reached no conclusion.

It should probably be said that a few years ago I heard that the driver’s ed teacher got fired because he got a DUI. I also remember him spelling the word mirror
m-i-r-o-w. I’ll probably let my wife set the door locking policy.

I had always heard the same thing as your wife – keep the dorr unlocked to assist emergency personnel. However, when I lived in NYC I was in the habit of locking the doors, and only unlocking them for highway driving. Now that I live in the midwest, I keep 'em unlocked as a general rule.

My doors lock automagically when I first pass 20 mph or so, and will not open from the inside unless you unlock them first. As Ed states, it depends on the vehicle model and year whether or not the inner handle will unlock the door. For parents, it may be a good idea to use parental lock out to keep the kids from jumping out of a moving vehicle (one of my cousins apparently did this at 55 mph).

From the National Highway Transportation Safety Administration:

Essentially, they claim that locking the doors with good locks significantly reduces your chances of being ejected from the vehicle. If you wear a seat belt, it seems likely that any crash that would disable you severly enough to prevent you from unlocking the doors from the inside would injure you sufficiently that in almost all cases it would be preferable to remain in the car until emergency personell can extract you safely. Note that (Pintos notwithstanding) most cars do not catch fire even in the most severe of accidents. And, even in the rare case, a bystander could break the window with a jack handle and unlock the door.

Well, here’s the thread I was talking about earlier. After looking through it, it doesn’t seem like the question had a real definite answer. But, as Duck Duck Goose pointed out in that thread, if you’re wearing your seat belt, it’d be very hard for you to fall out with the door open. Maybe, if the entire seat came loose from its bolts, but in an accident that severe, I doubt there’d be any survivors.

Joe, I skimmed the link you posted, but couldn’t find anywhere where they talked about locked vs. unlocked doors. They talk about improvements to door locks and latches, but are silent about whether the doors are actually locked or unlocked.