The 5 year study was conducted in 11 French departments (county/region) and analyzed by the Centre for Studies and Expertise on Risks, Environment, Mobility and Planning (CEREMA). The study showed that the participating regions saw a 12 percent increase in accidents.
The study did show that educating car drivers has a positive impact on reducing crashes. A second study is pending to review how to make lane splitting safer for all parties through education, speed control and more.
The result of this second study should hopefully align with a US study which stated that although front end collisions (by the motorcyclist) went up with lane-splitting, the odds of being rear-end went down significantly.
Read more about the French study here https://www.femamotorcycling.eu/french-lane-splitting-experiment/