Apparently utilities and other transmission developers brought 55 miles of high-voltage transmission lines into service in 2023. However, high-voltage transmission construction — 345-kV or greater — has fallen since the early 2010s when about 1,700 miles were added each year on average, according to a report. High-voltage additions fell to 925 miles on average from 2015 to 2019, and 350 miles a year from 2020 to 2023, the same report said.