Safety situation in the country improved very much in the course of past years. Red Khmers are not a threat any more. However, the mines are the biggest danger which is threating you. The Cambodia belongs to one of most with mines infected territories of the world. It is estimated that still 4-6 millions of pieces of mines are set snares for. So, you are recommended not to walk outside reserved paths. During vehicle (or motorcycle) driving, would you avoid your drive outside roads, please.
On the other hand, the pickpocketting as well as robberies are rather bigger problem in Vietnam or Thailand as in Cambodia. Despite this fact, you would be always on your guard and do not offer uselessly a chance to street robbers with your own inattention.
Traffic Police: 023 722 067
Information and warnings on travelling abroad is to be found HERE.