Section+6,+Chapter+1

What do you think? 1. I think it would help drivers decide if they should go or not because they would have a better idea of how much time they have to pass through the intersection or stop. 2. A yellow light might make them think that they still have a little time left, so they accelerate, however the amount of time they had was less than they though, and they get hit by a car coming from their left/right.

Group summery of the investigation 1-4. By determining speed and distance, if it is safe to accelerate. Video 5-9 Distance where it would be safe to accelerate.

1-4 part B Go zone, stop zone. Compare and contrast

Investigation

Assume

Light just turned yellow constant speed decide instantly

1. A. I think that the SUV should have stopped because it wasn't even at the intersection before it actually reached the intersection. I think the cab should have gone because it was already in the intersection, but I think that when he saw the yellow light, he should have slowed down. When you decide, stay at the same speed, or speed up. B.

2. A. I think that the cut off point for a yellow light should be around 4 meters. It is better safe than sorry. Uncertainty zone is from 4-8 m

B.

3. A. Automobile B can make it through the intersection.

B. I think that Automobile B is in the go zone because it is at the intersection at the point when the light turns yellow.

C. Any vehicle closer than automobile A would be in the go zone.

D. I think that C is not in the go zone because it is too far away from the intersection as it turned yellow. If the driver tried to make it through, they risk running a red light and getting hit by a car or hitting a car.

4. A. Automobile E is in the stop zone.

B. Automobile F is not in the stop zone. If they try to stomp on the brakes before the intersection, they can be rear ended, or they might end up in the intersection.

C. A, B, and C would be in the stop zone, while D, E, and F would be in the go zone. Since it is already known that D and F are in the go zone, assuming that E is between them, it would also be in the go zone. It is also known that D is somewhat in the Grey Zone, so anything behind it would be considered in the stop zone.

5. A.

B.

C. If you are traveling at a velocity of 30m/s, and the yellow light is 3 seconds, then you have to be within 90 meters of the other side of the intersection to cross. If that time was increased to 3.5, then you have to be 105 meters from the other side of the intersection.

6. A. The go zone would be 155 meters from the intersection.

B. The go zone is increased to 182.5 meters from the interection.

C. Yes, changing the length of a yellow light allows for a driver to get through a yellow light from a farther distance. Approximately 17 meters farther.

7.

A. Yes it made sense to me, such as when you increase the speed limit, then you can cross a wider intersection or cross with a shorter yellow light.

B. Increasing the length of a yellow light increases the go distance. Increasing the response time would decrease the stopping distance. Increasing the velocity increases the go zone and stop zone. Increasing the negative acceleration decreases the stop zone. Increasing the size of the intersection decreases the go zone.

C. Go Zone= A10*A4- A16. Stop Zone= A10*A7-A10^2/(2*A13)

D. The go zone is calculated as such because the time the car has to pass is the yellow light time. That, multiplied by the velocity equals the distance it travels in that time. Take the answer, then subtract by the width of the intersection, and you have the distance from the intersection which would be safe to cross.

E. The reaction time affects the stopping distance because it makes the driver decide if they have time or not, in which time they move closer to the intersection.

SECTION 2 OF INVESTIGATION

1. A. For vehicle A, I would stop

Assumptions for the go zone. Don't slow down, constant speed

Assumptions for the Stop Zone Negative Acceleration to break Reaction Distance.

Intersection Width Distance you must travel to cross safely

Things that increase go zone yellow light time, intersection width, your speed

Things that increase the stop zone Negative acceleration, speed, Reaction distance. Yellow light time

As you increase the time of the yellow light, you have more time to go through the intersection