Embellish the walls of the bedroom. Since there isn't a specific color that ties in with a transportation theme, you can paint the walls of the space in your little boy's favorite color. To incorporate the transportation theme onto the walls, use different types of plane, train and car decals or paint these items directly onto the walls freehand or with a stencil. Another idea is to paint a black-and-white checkerboard onto a focal wall to create the look of a race flag.
Incorporate textiles that feature transportation-related elements. Make the bed with sheets that feature planes, trains and cars and top them with comforter that showcases a single mode of transportation or one that also features different types of transportation. Hang curtains that include a transportation element, be it a mode of transportation or a transportation accessory, such as street signs, railroad crossing signs or stop lights.
Use furnishings that correlate with the theme. A prefabricated car bed is a fun place for your little one to sleep and fits in well with the theme. Alternatively, you could paint a transportation scene on a wood headboard, such as planes flying through the sky or a train traveling on tracks. Use stencils to paint different types of vehicles onto the surfaces of a toy box and on the sides of a shelving unit.
Complete the look of the room with decorative elements. Hang street signs, license plates, a stop sign or a railroad crossing sign on a wall. Purchase a decorative traffic light that lights up that will double as a night light for your little boy. Suspend train tracks from the ceiling and place a working train on it, or set up model trains on the floor where your child can play with them. Instead of trains, you could suspend model planes from the ceiling. Set out the little boy's toys on wall shelves, where he can easily reach them and they can also add to the look of his room.