Two days in advance: Make cookies. Roll out dough 1/8 in. thick. Using patterns, cut 10 buildings in each size. Using cutters, cut train engine, 2 cars, airplane (trim off wings and bottom of tail; bake wings separately) and 3 trucks (cut front end off 2 trucks to make passenger cars for train). Bake and cool cookies. Prepare 2 recipes of color flow icing. Outline and flow in cookies with color flow. Let dry overnight. When dry, pipe details with full-strength color flow. Add tip 3 dot lights on vehicles and tip 1 outline spokes on train wheels. Overpipe roof of train cars with tip 3. Pipe tip 3 outline windows on buildings (pat smooth with finger dipped in cornstarch).