Safe Routes to School (SRTS) funds that are part of the Federal SRTS program can be used by private schools. However, the infrastructure changes that are made with the funds must be within the public right of way or on the property of schools that are publicly owned. Therefore infrastructure changes, additions etc that are on private property are not allowed.
Each state may have additional regulations on how the Federal program money can be used. To learn more about the use of the SRTS funds for private schools contact the SRTS coordinator in your state.