could you dedicate a whole workout just to traps and forearms?

[LeanDario]

the workout would be short, low volume, 3-4 reps
example

Barbell Shrugs or DB shrugs: 3-4 sets x 15-20
behind the back barbell shrugs : 3-4 sets x 15-20
and then like 2 forearm exercises

itd be quick 30 min max workout, but would I be overtraining the traps and forearms?

[kievbison]

It's your workout - you can do whatever you want.

Your body will respond and adapt to the stress you put on it.

Do this for the next three months and report back to us how it went.

[m314]

Add some farmer's walks. Deadlifts too, although those work a lot more than traps and forearms. Deadlifts with a double overhand grip give me a better forearm and trap workout than anything else, but they also work quads, hamstrings, glutes, lower back, lats, etc.