Nothing like that in the UK but socially you are expected to help and do your best up to your level of expertise. Even doctors and nurses are not trained in first aid as a matter of course and would not be expected to set limbs or do brain surgery unless that is their expertise and they had the equipment. Bu if you have the knowledge and equipment, say a defibrillator, you may use it without fear.

We have a 'good Samaritan' ruling by the courts which indemnifies you against problems if you follow the above rule.

Our health and safety rules demand that you train and supply equipment to meet any 'reasonable and foreseeable' event whilst at work. i.e. a little if you are two people in a city office (Dial the emergency services). A lot if you are working on pylons in back of beyond four hours from help. If you work with poisons you keep the antidotes. Horses for courses.

They do not expect a response to a traffic accident beyond what the general public would do, thus the typical car kit supplied covers everyday cuts, scratches and burns. I also recommend eyewash sachets.