If all obvious attempts fail, try the following:
Hit door panel with your hand, just below the outside door handle.
As hard as you can.
Use a foam pad to avoid damage to the door, (and your hand).
It has been known to work!
It worked on my car!!
remove the interior door panel. you will see a metal rod connecting your interior and exterior door handles. most of the time the rod comes loose from one or the other. reconnect the rod. theres not much space so you might need a pair of needlenose pliers. if that still doesnt work inside the door to the rear is a trip lever that after pulling will open the door. the lever can be stubborn but it will open the door. any service center should be able to open it for you.
If the door is jammed shut, it will not be possible to remove the door trim on most cars without destroying it. However, if you are able to roll the window down you should be able to insert a thin piece of metal (ie. wire coat hanger, slimjim etc.) and manipulate the door handle rod inside to pop it open. This is possible only if the reason behind the jam is mechanical and not structural.
break the window then get in
because a seat belt might be jammed
Push very hard on the door so that the latch seats completely. Then, open the door.
In general, the moving car would be at fault because pedestrians always have the right of way. However, under certain circumstances, it could be the door-opener's fault.
the person who parked the car
Try to get to the handle in side of the window or you can try to brake in to the panal and look at whats getting jammed.
I would say you both have the responsibility to watch out for each other's lives and possessions. The person opening the door should have been aware of being in a parking area and therefore should have anticipated wether a car was coming or not. The person driving the car should have known that people in a parking area move around cars to either get to their car or move from it. A person opening a car door is a much occurring action. I would say the person opening the door is most likely to be blamed since he/ she had to take more precautions.
How are the hinges? If the door drops down when opened, then the hinges are worn out. If the hinges are fine, then adjustment to the striker/bolt assembly is needed. This is very simple, and once you take a look at it, you'll see what to do.
A car door is a second class lever. The fulcrum is the hinges, the input force is the person opening the door, the output force is the way the car door swings, the bar is the door, and the load is the force put on the door.
There is usually a label stuck to some part of the driver's door or door opening that tells the year that the car was made.
Buy a can of lock unfreeze or wd-40