We will be participating in the CASTO Annual Conference in Sacramento on March 28, 2015. California Association of School Transportation Officials, better known as CASTO, was founded in 1968 to promote safe pupil transportation for all California children. We are dedicated to the safety of all children through education and training in every avenue of transportation.We will be participating in the CASTO Annual Conference in Sacramento on March 28, 2015. California Association of School Transportation Officials, better known as CASTO, was founded in 1968 to promote safe pupil transportation for all California children. We are dedicated to the safety of all children through education and training in every avenue of transportation.