In The Netherlands you are supposed to clear the road right away and not wait for the police, as long as there are no personal injuries. This is because a blocked road creates the risc for more accidents and traffic jams are an economic harm. Settlement of the material damage is another thing. In this case insurance companies do not require police reports. Parties are supposed to carry with them the standard European damage form, fill it out together, sign it and send a copy to their insurance companies. Then the insurers will settle. The form requires a sketch and a text about the accident from both parties. Photos are not required, but now that most have a camera phone, they might be useful. So, I would advise to go for better arrangements and not for more proof for more complicated, more costly law suites.
In case there are personal injuries, then it is a police job anyway, which is not only about taking photos in a professional way.