An automatic emergency call system is mandatory for new cars in the EU by march 2018. The call works via cell phone technology and is depended on reception the position is determined via GPS. If the system is triggered the car is called by the coordination center for assessing the situation. If the user does not cancel, a response team is sent. The system will usually also have a manual switch for the emergency call.
This may also be useful when people start to help at the scene of the accident and forget to call emergency response.
Hope most new systems will be free of use (emergency call are free, so that should be possible); I have seen subscription-based systems with emergency calls as an option.