Transportation Data Science:

https://github.com/uky-transport-data-science/ce599

Programming:

https://cscircles.cemc.uwaterloo.ca/

Statistics:

https://www3.nd.edu/~rwilliam/stats1/index.html 

https://www3.nd.edu/~rwilliam/stats2/index.html 

https://www3.nd.edu/~rwilliam/stats3/index.html 

Machine Learning:

https://www.statlearning.com/ 

https://web.stanford.edu/~hastie/ElemStatLearn/ 

https://see.stanford.edu/Course/CS229 

https://ubc-cs.github.io/cpsc340/

Deep Learning:

http://neuralnetworksanddeeplearning.com/ 

http://www.deeplearningbook.org/ 

https://d2l.ai/