A study shows there is no evidence to prove California's cell phone ban has any effect in decreasing the number of car accidents in the state.
Professor Daniel Kaffine from Colorado University at Boulder says he expected to see a correlation.
"When we go to the data, we just didn't see any evidence that accidents actually declined in the six months after this ban was put into place," he said.
The study showed driving while on a cell phone may not be as dangerous as driving while intoxicated, like it was previously thought.
Kaffine says a number of reasons could be to blame, but points out people might have not obeyed the new law, skewing the numbers in the study.