Marostica has served on over 60 boards and commissions in the Loveland area, with an emphasis on transportation-related issues (Loveland Transportation Finance Committee, Loveland East-West Mobility Study Committee, Loveland Eisenhower Boulevard Alignment Analysis Committee, Fort Collins-Loveland Airport Master Plan Update Committee). He has also served as the chair of the board of directors of the Poudre Valley Health System Foundation and the Medical Center of the Rockies Foundation, and on the bond oversight committee for the Thompson School District. He is also an avid motorcyclist and regularly participates in the Sturgis Motorcycle Rally and Ride to the Wall, a cross-county ride ending at the Vietnam Veterans Memorial.