Police say the man, who is in his 50s, was driving along Weeton Road near to the A585 junction at around 10.45 on August 30 when the incident happened.
The man suffered serious injuries to his hand but said his steering wheel, which blocked the path of the piece of wood, most likely saved his life.
He said: "A pìece of wood came off builder's flat bed lorry going in opposite direction towards Weeton. The steering wheel saved my life but my right hand got badly injured."
Police are now trying to trace the owner of the builder's lorry.
PC Chris Long, of Lancashire Police, said: “The timber has struck the victim’s windscreen, causing damage to the dashboard and bending the steering wheel.
“The wood has also damaged the driver’s hand, causing injury to the index and middle fingers.
“The van involved was described as a new-looking white transit or sprinter-type pickup with a slightly enclosed back. It was carrying a quantity of cut timber in the rear.
“The vehicle did not stop at the scene, but it is possible the driver was not aware of the load loss.
“We are keen to speak to anyone who can assist with our investigation.”
Anyone with information can contact police on 101 quoting log reference 0423 of August 30.