One of the most dangerous moves to make when driving is turning left. Left-hand turns lead to many accidents because of their inherently dangerous characteristics.
Popular Mechanics explains left-hand turn accidents typically happen at intersections when the car turning left does not have a traffic signal allowing them to make the turn. But, they can happen anytime a car turns left for multiple reasons.
The design of a left-hand turn is to cross oncoming traffic. Any time a vehicle must pass the center line, it increases the chances of an accident. Human error, visibility issues and other vehicles not paying attention are all factors that make crossing the center line dangerous. The driver has to be alert and aware to make the turn safely, which can be tricky in some situations, such as busy traffic or where the line of sight is not clear.
There is also the issue that another passing vehicle could introduce a crash. If drivers behind the turning vehicle are not aware of what is happening, get impatient and decide to pass, they could collide with the turning vehicle.
Unfortunately, there is no one-size-fits-all solution to the risk. In some cases, a driver can take three right turns to end up going in the direction they need instead of turning left. Right turns are less risky. Turn lights can also be helpful, but not all jurisdictions have them in place. Roundabouts are also an alternative option, but they require major construction and traffic flow alterations.
Without major overhauls of the roadway, the best solution to keep left-hand turns safe is for a driver to pay attention to all traffic and only turn when it is clear.