Brilliant! It's a shower curtain (liner) taped to the kitchen floor. The road is drawn on with permanent marker and the kids can color to their hearts content then drive their cars on it. This would be great for drawing a giant map, too!
Backyard chalkboard--less mess and the rain washes it away--such a good idea! use birch plywood. First we painted the front and back with primer to seal it, and then we just painted the front with a quart of chalkboard paint. He attached it to the fence with galvanized wood screws. So far so good, it's been 9 months and it looks brand new.