One person is in hospital after two cars crashed on the Monaro Highway, south of Johnson Drive in Tuggeranong.
The incident and debris from the crash were reportedly blocking vehicles on the road, as of 1.45pm.
The highway was closed, but an ACT Policing spokeswoman said police had opened one lane in both directions as of 2.30pm and continued to direct traffic.
She said one driver was taken to the emergency department with injuries that were not significant.