Dynamic Visual Obstruction is the term for when a moving vehicle blocks another vehicle’s sightlines. A common place where this occurs is at left turn lanes as demonstrated in the video below.  

There are a raft of ways to reduce this risk, including:  

  • Altering the intersection form (e.g. roundabout) (Primary) 
  • Slowing vehicles on the approach to the intersection (Supporting) 
  • Offsetting the left turn lane to open sight lines (Supporting) 
  • Adjusting the positioning of the hold line (assuming it can be done safely) (Supporting) 

Like always, a site-specific solution is required, but the reduction in rear-end crashes with a left turn facility can often lead to increases in other crash types.