When approaching a vehicle that is turning towards your direction of travel it may block your lane for many seconds if it is a slow moving vehicle such as a tractor-trailer pulling from a stop.

In this case a tractor-trailer pulled out from a driveway and was impacted by a car headed the opposite direction. The road was straight, well lit and relatively flat. Both driver's had a good view of each other and the collision could have been easily avoided by the tractor-trailer waiting to pull out when there was more space, or the driver of the car letting off the and/or swerving to avoid the truck. Given the speed of the car, letting off the gas 3.6 seconds before impact would have been enough to avoid the collision.