While the front and back ends of a vehicle can absorb significant force, the same is not true for doors or side panels. In some cases, there are only a few inches of protection between a driver and the oncoming car. If the other vehicle is traveling at a significant speed, it can crumple the door inward and severely injure a driver or passenger.
Side-impact collisions frequently occur at intersections. In many cases, they occur due to one driver entering an intersection without the right-of-way. At high speeds, a side-impact crash in an intersection could be especially dangerous.