Power Line Works In Progress (T4-5)The Power Line Works In Progress (T4 5) sign warns motorists and pedestrians that electrical line work or maintenance is being carried out ahead. This advance notice helps drivers slow down and navigate safely, reducing the risk of accidents in high risk areas. Manufactured from yellow CL400 Class 1W reflective material, the T4 5 ensures excellent visibility during the day, at night, and in adverse weather conditions, keeping both workers and the