A lot depends on how the local police and courts interpret the law. Some allow anything that is sensible and is not specifically prohibited. Others will arrest and fine you for anything that is not specifically permitted.
In the US, a few states do not prohibit lane splitting while they don't necessarily have laws that permit it either. In California, for example, on freeways and some multilane highways and streets, the highway patrol will allow you to split lanes while the traffic is moving at less than 30 MPH as long as you don't exceed 30 or 15 MPH faster than traffic speed, whichever is slowest. You have to split between lanes going your way, no riding down the berm or centre of the road. If a patrolman takes a disliking to you, he can get technical and give you a ticket for not signaling for a lane change if you cross the line between lanes, but that is rare unless you are behaving badly.
Where I live now, it's not really an issue because there just isn't that much traffic.
