Hello Emily!
Firstly I want to comment on how interesting your topic is as well as the high quality and number of your tables and figures. The tables are simple and easy to understand with the use of the captions. One potential suggestion is to use a box plot for table 2 or in addition to table 2. This would help create a more of a visual. Figure 2 is particularly excellent as you used colors to illustrate multiple variables responsible for the number of collisions.
Another potential suggestion is in your table of contents. I suggest making results its own section, namely section 3, separate from the data section.
The results section is well written and explains what is seen in the tables and figures without going into the why - great work.
As for the discussion, it would be useful to add a short summary of the paper, explaining possible explanations for why the data looks the way it is, what you learned that can be applicable in the real world as well as areas of weakness and suggestions for future work. It looks like you weren't quite done with this section but wanted to comment on it just as a reminder :) Your appendix section is well used.
In terms of code, your references section is well executed. Your use of comments to explain the purpose of each package used is excellent and easy to follow. Your data section code appears to be straightforward. Though you do use some comments, I think it may be useful to use more in the data section particularly in lines 92 to 103, 125 to 152, 165 to 181, 190-193, 204-210 as no comments are used. Here i'd like to know exactly what you'd like to do and how you get there. I suggest more consistency in using comments so that when others are looking at your code, it is clear what your intensions are.
Overall I think this is an excellent paper and I can tell your research was through. I can also tell this subject is of interest to you as you carried that passion into your introduction and throughout the entirety of the paper. Well done!