critical need to drive, california?

Hi, I recently got arrested for possession of alcohol in California. I am 18 years old and realize that my license will be suspended for a year. I know that I can apply for a "critical need to drive" sort of thing to allow me to drive to and from work/school or to see an ill family member. My mom is always working throughout the day and cannot bother to take me anywhere. And, my brother, the other driver in the house is still in high school and his schedule is completely different from mine. Also, with work, the hours I work are odd and the buses do not always run at those times. Plus, the buses are garbage and sometimes they never even come! Also, one of the colleges I plan to go to does not have a bus system near it in order to get there. But, regardless. I am wondering under these circumstances, what are my chances of getting my critical need to drive license approved?? It is very important to me. Please answer.