Cal. Code Regs. tit. 5 § 15241
For the sole purpose of determining the total current expense for transportation of a district on which reimbursement is based, the following minimum transportation distances, measured from the point a pupil boards a bus at a regularly established stop to the school of attendance by the shortest traveled road, are set for normal pupils.
For pupils attending kindergarten or grades 1, 2, or 3--three-fourths ( 3/4) mile.
For all other pupils attending an elementary school--one (1) mile. For all pupils in grades 7, 8, or 9 attending a separately maintained three-year junior high school--one (1) mile.
For all pupils in grades 9, 10, 11, or 12 attending a four-year junior high school or a high school--two (2) miles.
For all pupils in grades 13 or 14 attending a junior college--three (3) miles.
Cal. Code Regs. Tit. 5, § 15241