If you have a traffic accident in Costa Rica, leave the vehicles where they are and call both the Transito (Traffic Police, at 222-9330 or 222-9245) and the INS known as the insurance investigator at 800-800-8000. Both of these officials will come, eventually, to the accident scene upon notification and file their reports. Only after they do so can you legally move your vehicle.
This may cause great traffic back-ups but drivers are used to this type of obstacle and will find a way to get around you. I’ve seen traffic up on sidewalks and driving at the edge of a very scary drop-off to get around an accident. So don’t worry about blocking the road. Stick to the rules or the alternative will make you crazy. Remember my radio story?