I have a respectable cGPA of 3.5 and annual GPA of 3.7. I am hoping to graduate with at least a cGPA of 3.5 which would award me with "high honours". I am not trying to find an "excuse" for a low GPA (since mine is rather high), but rather emphasize that I was able to achieve those marks while volunteering / commuting. I am hoping this demonstrates my hard work. Anyways, I volunteer on research 3 hours a week (not a huge time commitment). However, I also commute 5 hours total to and from school (so about 25 hours a week simply commuting). I am wondering if this would be worthwhile to mention in my letter or if I should leave it out? I am definitely mentioning my volunteering since it relates to the program.
I'd advise against bringing up anything that might seem like an excuse, so I'd forego mentioning the commute. That said, this is an EXCELLENT thing to have mentioned in a letter of recommendation that reinforces your dedication. Try to get a recommender to bring it up.
I agree with @BryanKrause.
I would avoid mentioning anything related to your commute. To the outside observer this appears to be "your choice" thus you will have to deal with the consequences of that decision (i.e. 5 hour commute). Additionally, these hours spent are percived as "wasted" because the other person with the 1 hour commute has more time for thier studies & research.
Some context for my answer: My relative's commute was 3 hours each way for almost 15 years. Often, employers, colleagues & even strangers told me her she was crazy. In many cases, this cost her the job & when that was not the case she was advised to downplay the commute.