The provision of traffic signals at intersections

The provision of traffic signals at intersections is primarily intended to control and regulate traffic flow.

Traffic signals help in reducing right angled collisions (also called angle or T-bone collisions) because they control the movement of vehicles crossing paths.

However, the sudden stopping of vehicles at red lights can sometimes lead to an increase in rear end collisions, as following vehicles may not always stop in time.

Therefore, traffic signals reduce right angled collisions but may increase rear end collisions.

Hence, the correct answer is Option C: reduces right angled collisions but may increase rear end collisions.