The first example is the train that only implements all the basic features without any of the bonus points. The code is easier to read and heavily-documented. The code is in tr-03-01-01.js

The second example is the train demo and the basic train (without all the advanced points). The code is easier to read. The code is in tr-03-01.js

The third example is the train that implements all of the bonus features without any of the artistic merit points. The code is heavily-documented to explain the algorithms used. The code is in tr-03-01-02.js

The last example is the train that implements all of the bonus features with all of the artistic merit points.