The word "traditional" is usually applied to distinguish whether an IRA (or 401k, or 403b, etc.) is "traditional" (no tax at contribution, but taxable at withdrawal) or "Roth" (post-tax at contribution, not taxable at withdrawal). "Taxable" is just taxable.
But more to the point: you can't just convert savings to an IRA - you can contribute up to the amount of "earned income" you have for that tax year. Assuming (true?) that, if you do have earned income as a student, you pay little or no federal income tax on it, Roth may be best.
If you can't do an IRA, and you don't the money in savings any time soon (given that you are still in school, that may be a bad assumption), then taking it out of savings and putting into a good index fund seems a fine idea.
See the
case study sticky for the info needed (as applicable) if you want a more detailed reply. Good luck!