Union Pacific is applying white paint to sections of rail in high-heat areas of its 32,000-mile network to reduce rail temperatures and lower the risk of thermal misalignment.
The method uses a high-rail truck and paint sprayer to apply white paint to both sides of the rail. According to Union Pacific, the paint reflects sunlight and has reduced rail surface temperatures by about 20 degrees.
Thermal misalignment occurs when steel rails expand in high temperatures and lateral forces push the track out of alignment. Union Pacific continues to rely on rail anchors, fasteners, maintenance and inspection practices as the main controls for managing heat-related track conditions.
The railroad began targeted deployment of the rail-painting method in high-heat areas in 2025. Union Pacific described the approach as a combination of European rail practice and U.S. road striping techniques.
Union Pacific said the measure adds another layer of protection across its network rather than replacing existing track maintenance and inspection procedures.
