Alexa Middlelaer died after she was hit by impaired driver Carol Berner as she was feeding a horse in a field by the side of a road.
Her parents are suing Berner, Delta and the ministry of transportation.
The Middlelaers allege that the municipality is partially responsible because an engineering report they commissioned suggests that speed bumps on the rural road were too close together, and could have been a factor in the crash.
A provincial court judge has ruled that the lawsuit should proceed, but Delta has applied to the B.C. Court of Appeal seeking to be dismissed from the civil lawsuit.
Delta's lawyer Eileen Vanderburgh says the two speed bumps on the road where Middelaer was killed are appropriate and properly set apart from each other.
She says Delta's responsibility is to make roads safe for average drivers, not dangerous ones.
After the death of their daughter, the Middelaers have become outspoken activists against impaired driving.
Berner was sentenced to two-and-a-half years in prison for the deadly crash. She recently began to serve her sentence after her second appeal was dismissed.