Many head-on collisions occur on two-lane roads when passing because

misjudge the closure rate of oncoming traffic

Explanation:

Many head-on collisions occur on two-lane roads when passing because drivers misjudge the closure rate of oncoming traffic. Some drivers tends to miscalculate the speed and closure rate of oncoming traffic thereby taking decision that leads to collisions and accidents. Drivers should always account for safety and effectively estimate closure rate of oncoming traffic before passing or squeezing in front of them.