Recent study from the Johns Hopkins Bloomberg school for Public Health found that:

* Overall, bike lanes in Baltimore improve cyclist safety

* Without bike lanes, drivers had trouble sharing the road with cyclists

* One in six Baltimore drivers, or about 17 percent, violated the 3-foot law

* Researchers found a 20 percent increase in motorist adherence to the 3-foot law for bike lane streets compared to standard streets.

Summary at Streetsblog 3 foot passing compliance - bikelanes improve safe passing in Baltimore

and link to Johns Hopkins study Is 3 foot law working in Baltimore?