The unthinkable can happen all too easily. In the large vehicles that many of us drive, a significant blind spot to the rear below the window line can hide children playing behind your vehicle, and the consequences can be tragic.

As a result of as many as two children a week killed in back-over accidents across the U.S, rear-view cameras will become mandatory in all cars from 2014.

Some makers already offer the cameras as options on their vehicles, but most people think of them as parking aids rather than safety measures. For anyone with children, the cameras should be a very important consideration. It's not always possible to keep your kids in view the whole time and when there are cars moving about, being able to see where they are is paramount.

Even your own driveway can be dangerous. Three children have been killed in the last week in New Mexico, and two of those were on driveways. It's easy for a kid to run behind the car without you even noticing and a quick glance in your mirrors may not be enough to spot them.

Janette Fennel from charity Kids and Cars highlights the risk: "I don't think anyone would buy a vehicle if we couldn't see 20 feet going forward but we are buying vehicles where we can see that or more going backward."

Of course, you don't even have to wait until 2014 for cars with rear-view cameras. Aftermarket kits are available for as little as $100 right now. It's a small price to pay for a kid's life.