Please review traffic calming theory and practices in the publication: "Traffic Calming, State of the Practice", by Reid H. Ewing, published by the Institute for Transportation Engineers, 1999. This is an excellent resource for understanding what traffic calming is and is not, different techniques for traffic calming, engineering and aesthetic issues, traffic calming impacts, advantages and disadvantages, emergency response and other concerns, and other issues. There are other methods to use besides "speed bumps", and you need a broader understnading before you select your method. Good luck,
Mikolay