```json
{
  "TragedyDegree": 2,
  "ComedyDegree": 6
}
```

**Explanation:**

1. **Tragedy Degree: 2**
   - The story has almost no tragic elements. While it mentions some obstacles and challenges faced by Ava, these are not emotionally devastating or profoundly tragic. The tone is primarily hopeful and forward-looking.

2. **Comedy Degree: 6**
   - The story is relatively light-hearted with some elements that evoke positive emotions. The successful implementation of the new transportation system, the community's excitement, and the overall celebratory atmosphere lend a sense of happiness and fulfillment. However, it doesn't reach the level of strong comedic aspects or an extremely happy ending typical of a higher comedy degree score.
