Locking or not car doors, which is safer.

Hi all.

Lets assume you have a modern car, about 8 years old give or take. You always wear your seatbelt. You always drive with the windows up. You have frontal driver and passenger airbags but no side airbags.

Is it safer to drive around with the doors locked or unlocked. Lets also assume car jacking is not a consideration here.

On one hand, if the the doors stay closed (seems more likely if they are locked), seems to me that really helps the overall structural integrity if you have a rollover type of accident.

On the other hand, if your electrical system gets crapped out, and the doors are locked and windows dont work, a relatively minor accident could get ugly fast if fire or water were involved.

Then again, if the doors are unlocked, maybe you’ll get lucky and get “thrown clear” and all you’ll suffer are minor injuries :slight_smile:

I’ve never heard of a car whose doors don’t unlock when the inside handle is pulled.
So, this is a non-issue.

Could be an issue in the back when the childproofing locks are engaged, though I don’t know what happens then if the electrical goes out. My WAG would be that the safety locks ought to disengage then.

Every vehicle I have owned the doors stay closed and locked when you pull on the inside door handle, the door has to be unlocked to open the door.

My 2002 Escape’s doors open from inside even if locked. I agree about the back seat doors and child locks, but otherwise I think most open.

Having the door locked is one more barrier against a person falling out of a moving vehicle. It does happen for various reasons.

Locking the door doesn’t add anything to the impact resistance of the latch. IOW, there’s no reason to believe a locked door is more resistant to popping open than an unlocked door. So there is no benefit to locking the doors, at least from a crash survivability POV, and there are plenty of disadvantages.

My car has a feature that the doors automatically unlock during a collision. The same logic which fires the airbags unlocks the doors. So at least one engineering team figures that’s a net benefit in a crash.

My doors automatically lock when my speed reaches 10 MPH. So unless I’m cruising around at <10, it’s a moot point.

These two circumstances are very rare. Plain old rear-end, T-bone, head on and hitting a stationary object crashes are the norm. Cars rarely burst into flame.

What LSLGuy said.

There is no other structural integrity added to the car with a locked door. Locking a door just removes the ability to open it with the handle.

Some cars automatically lock the doors as you start the engine or start moving.

I recently rented a Chevy Impala that had this ‘feature’ I hated it as did every one in the car.

Some cars also auto lock if the keys are out of it. I’ve been very nearly locked out of my Nissan because of this absurd feature. It is a bit of a pet peeve of mine.

Maybe that’s how it got its name. :slight_smile:

I’ve never had a car which does that.

I keep my doors unlocked except in a rare instance where I think someone may want to make trouble. For example late at night in an area where there are lots of agressive, drunk pedestrians. Very rare, but it has happened once or twice.

Actually there is another time when I lock them. When, for whatever reason, I need to have something valuable on the passenger’s seat which could be easily grabbed.

If you get locked inside your car, have your wife follow close behind with a golf club to rescue you.

Always unlocked. Even if the inside door handle overrides the lock, you may not be in a condition to operate it. You definitely want a rescuer to be able to open the door!

Every time I get into a customer’s car where the autolock has been set (a driver programmable item) when the doors lock, I think to myself, I have many fears in this life, but being car jacked at 75 MPH is not very high on the list.

I had no damned idea that you could open my car doors in motion and try to escape. Found that one out today. Some people have to have their drinking rules seriously revised.

On the other hand, the doors on MY car don’t have electrical locks. Nor are the windows electrically operated. Old fashioned mechanical ones. And on my truck the rear window on the cab has a manual locks as well.

I’m not sure why, but I always lock my doors. I just can’t stand to have them unlocked (no fear of car-jacking anywhere). And so, I program my locks to auto-lock. But, I also program them to auto-unlock when I put it into park. In a bad neighborhood, that could be dangerous, I imagine.

I need to get back to this thread, but too busy at the moment for replies to specific posts.

I do recall back in the day when mechanical locks were the norm, standard instructions called for locking the door once you got inside. I seriously doubt that was to prevent car jackings, which would imply to me that somebody thought that doors being locked was safer than being unlocked.

Depending on when this was, it might have been to be sure the doors were secured to prevent someone from falling out of the car while in motion. I still remember when I was a little kid (during the 1970s) riding with relatives, in the back seat of their car. I was in the middle, one of my aunts was on my right, my younger sister was on my left. The driver made a right turn into a parking lot and somehow the back left door flew open. My sister slid out but grabbed the door handle and frame, and I tried to disappear into the seat, frozen in horror, as my aunt reached over me to grab for my sis and the driver hit the brakes. I don’t know why the door popped open, maybe my sis had been playing with the handle, maybe she didn’t close the door firmly, maybe the latch was faulty, but it was pretty obviously not locked. That car didn’t have rear seat belts.

I remember the Car Talk guys joking that doors should be programmed to unlock at higher speeds (to facilitate rescue if you crash) and lock at lower speeds (to prevent theft and carjacking).