Parts of the Hume Highway were closed for more than an hour, after a car crashed into a boat that had fallen off a trailer being towed by another car.
The crash happened just after 5am on Wednesday on northbound lanes of the highway near Gunning, between Yass and Goulburn.
A Goulburn police spokesman said the boat came off the trailer it was traveling on before another car crashed into it.
It's not known what caused the boat to fall off the trailer.
All northbound lanes of the highway near the accident were closed for 90 minutes.
One lane has recently reopened to drivers.
No injuries were reported in the incident.