State jurisdiction over railroad safety is extremely broad, however most areas have been preempted by the federal government. The PUC retains primary jurisdiction over all public highway-rail crossings, including opening, closing, upgrading, overpasses or underpasses, and the allocation of costs. All economic jurisdiction over railroads that are part of the national railroad system come under the jurisdiction of the Surface Transportation Board.
In accordance with 49 CFR Part 659 and CRS 40-18, the Colorado Public Utilities Commission has responsibility for the oversight of the safety and security of rail fixed guideway (RFG) systems within the state. While the authority of the Federal Regulations extends to RFG systems which have received or are receiving federal funds under ISTEA., TEA-21, or SAFETEA-LU, the Colorado Statute grants this authority to any RFG system operating within the state, whether receiving federal funds or not.