Railroad Crossing Guard

The city council of the town of ChooChooville would like our company to design a railroad crossing for a railroad museum and park they are constructing near the city center. The crossing guard will prevent pedestrians from crossing the tracks of a miniature train ride that will circle the park. Here are the constraints of the design:

1. The crossing guard must have two touch LED lights that blink on an off to warn pedestrians that the train is approaching and that the crossing guard is coming down. Furthermore, the display screen (VEX IQ Brain) should give a warning sound and text for this event.

2. The speed of the crossing guard arm should be such that it will give pedestrians plenty of time to get out of the way.

3. An ultrasonic sensor must be placed a distance from the crossing guard (along the tracks) that will initiate the dropping of the crossing guard arm.

4. The arm should be down for a period of 20 seconds before it raises back to its original position.