When is comes to the safety of my vehicle, how far does my responsibility extend? Are unsafe modifications that contribute to a crash enough to put me at fault?
In the August 13, 2015 decision in Wheeler v. Lee, 2015 BCSC 1432 (http://www.courts.gov.bc.ca/jdb-txt/SC/15/14/2015BCSC1432.htm) Mr. Justice Kelleher considered liability in a case where the defendant driver’s trailer was inappropriately balanced due to the addition of an aluminum cargo box on the back. This decreased the tongue weight of the trailer such that it became unsafe. The unbalanced load caused the vehicle to sway and eventually flip, causing injury to the plaintiff. Mr. Justice Kelleher states that the defendant ought to have known what alterations would compromise the safety of his trailer, and that it is the responsibility of the operator to ensure that his vehicle is safe:
 The wind may well have been a factor in causing the mishap. But the evidence establishes that the percentage of the trailer’s weight that was on the coupling system fell below the manufacturer’s specifications. This in turn increased the likelihood of trailer sway.
 The defendant ought to have known that altering the trailer in this manner would compromise the way in which the trailer operated and in particular, could cause trailer sway. The owner manual makes express reference to this.
 I am satisfied that the defendant’s negligence was a contributing cause of the accident. There is no suggestion that the plaintiff had any role in causing the accident.
 The evidence establishes that the defendant’s decision to affix a large box to the rear of the accident and to load it with equipment decreased the tongue weight of the trailer and reduced the ratio to an unsafe extent. The defendant ought reasonably to have known that.
 For these reasons the defendant is liable for the injuries caused to the plaintiff.