Collisions+Due+to+Heavy+Traffic

Kai Farrell toc = **Collisions Due to Heavy Traffic** =

**Description of Driving Safety Hazard**
Often times, people do not slow down enough when they approach a yellow traffic light. This can result in a collision or gridlock. In order to avoid these accidents, it is necessary for the driver to know the following: We hope to teach everyone how to be able to know how to do all of these things when they need to.
 * The driver’s velocity
 * How far away the driver is from the light?
 * How long will the light stay yellow?
 * What is the length of the car?
 * What acceleration will the driver need in order to stop in time?

**Kinematics**
For this type of scenario, it is relevant to know all of the basic rules of Kinematics. This means formulas for finding both average and instantaneous velocity. You also should know how to measure acceleration. If you know what your current velocity is, how far away from an intersection you are, and how long the light will stay yellow for, you should be able to find out either how much you need to accelerate by in order to make the light, or how much you need to accelerate by in order to stop right before the intersection.

**Example Scenario**
A man is driving downtown in his new Toyota Camry during rush hour with a constant velocity of 7m/s. Like many of the other drivers on the road, he wants to get home as soon as possible so he can get to the tv before his favorite show comes on. Traffic is particularly bad today because the public transportation system has gone on strike. As he is 45 meters away from the next intersection he needs to get through, the light turns yellow. Hoping that if he accelerates by 2m/s/s he will make the light, he does just that. Unfortunately, he does not make the light and another car crashes into him. This indecent results in the man's death.

Graphs
The above position vs. time graph represents the man's displacement in the scenario. The time starts 3 seconds before the man is at the orgin (45 meters away from next intersection). The above velocity vs. time graph represents the mans velocity at a given time as he was driving. This graph takes place during the same time interval as the previous. The above motion map shows the car's velocity and acceleration at a given time. The orgin on this map is where the position equals 0 meters so that we can see what the car's velocity was before it hits the orgin. When the car reaches the orgin it begins to accelerate. Since the acceleration is constant throughout the entire time period until the car crashes, the acceleration arrows stay the same length whereas the velocity arrows increase. There is just a dot where the position equals 45 meters because that is the point where the car crashes and stops. Every dot on the acceleration arrows represent a second.

**How this Hazard Can Be Avoided With a Better Knowledge of Kinematics**
In order to avoid these hazards, people should learn some basic Kinematics. Things people should always be aware of while driving should be the length of their car, their velocity, their acceleration, and if possible, their displacement and the length of the traffic light they are trying to get to. If people were more knowledgeable about Kinematics, the road would probably be a much safer place.

**Conclusion**
As you can see from above, physics can save your life! Whenever you are driving you should always know your velocity, acceleration, and displacement. If you know these three things and how to use kinematic equations you should be safe. If you don't know how long a yellow light will last, assume it won't be long and SLOW DOWN! If you decide to go faster, you might get lucky, but you probably will not.