The government had lifted a vehicle ban on National Route 6 through the area where residency is restricted due to the crippled Fukushima No. 1 plant, the first time that stretch of highway has been open to automobiles since the nuclear crisis began in March 2011.
However, motorcycles, bicycles and pedestrians are still not allowed due to the higher risk of radiation exposure, officials said.
The 14-km section passes through the towns of Futaba and Tomioka.
The restriction was lifted after decontamination work was completed and damage to pavement caused by the 3/11 earthquake was repaired, the officials said.
With the road re-opened, local residents hope there will be an increase in economic activity in Fukushima and the wider Tohoku region because National Route 6 is a major artery. Some people, however, have voiced concern about a possible rise in crime with the increased traffic.
At midnight Sunday in Tomioka, workers removed a checkpoint barricade and let in a long line of cars that were waiting for the re-opening.