Each transit agency must establish and implement a Safety Management System under this part. A transit agency Safety Management System must be appropriately scaled to the size, scope and complexity of the transit agency and include the following elements:

1. (a) Safety Management Policy as described in § 673.23;
2. (b) Safety Risk Management as described in § 673.25;
3. (c) Safety Assurance as described in § 673.27; and
4. (d) Safety Promotion as described in § 673.29.