The friend suffered concussion, bruising and grazes.
Defence lawyer Richard Stone told Judge Bridget Mackintosh that there were no footpaths in the area and the weather was foggy at the time.
He said Janssen's friend was extremely intoxicated, stumbling onto the road as he walked.
Janssen told police he was driving about 40km/h and didn't see his friend when he accidentally struck him with his ute.
The friend was unable to work for six weeks and had difficulty concentrating.
His injuries were covered by ACC and Judge Mackintosh acknowledged that Janssen was remorseful of the incident.
"You did the right thing by seeking help, this was a serious matter."
Janssen was ordered to pay a fine of $1500 along with $150 towards court costs.
He was also ordered to pay $100 medical expenses and $109.25 for the ESR analysis.