“Lane-splitting appears to be a relatively safe motorcycle riding strategy if done in traffic moving at 50 MPH or less and if motorcyclists do not exceed the speed of other vehicles by more than 15 MPH.A significant number of motorcyclists lane-split in fast-moving traffic or at excessive speed differentials. These riders could lower their risk of injury by restricting the environments in which they lane-split and by reducing their speed differential when they do choose to lanesplit. ”
While I would rarely split if traffic was moving at that speed and in the UK that could be considered dangerous driving it’s interesting to see the study points at 15mph more than the traffic you are splitting. In the UK we are often told to not go faster than 10mph that the traffic. Though there is no official speed where it is a cut off point to dangerous driving (UK).
Never the less the document is interesting reading and you can view the entire publication here
University California Berkeley – Lane splitting safety california may 29-2015