There was a long traffic jam on the southbound carriageway of the Majura Highway in the rush hour after five cars shunted into each other nose-to-tail.
Police said that the southbound route was reduced to one lane. Traffic at one stage was down to walking pace.
The accident happened on the Federal Highway intersection, just inside the north-east corner of the ACT.
The accident happened at a notorious blackspot where traffic often leaves the federal highway at speed only to decelerate rapidly around a blind bend.
There was frost on the road this morning but it's not known if that affected driving conditions.
