I donated platelets at the Red Cross. Can I deduct the mileage to travel there?
Yes, as long as that is the sole purpose of the trip.
14 cents per mile driven in service of charitable organizationsIRS website - <a rel="nofollow" target="_blank" href="https://www.irs.gov/newsroom/2017-standard-mileage-rates-for-business-and-medical-and-moving-announced">https://www.irs.gov/newsroom/2017-standard-mileage-rates-for-business-and-medical-and-moving-announced</a>