Bridges, especially flyover models, differ from railways as they are three-dimensional rather than flat. To create an interlocking layer effect, color depth, contour lines, and shapes are primarily employed. The methods are categorized into three-dimensional and flat production techniques. The flat production method is typically used when the bridge is an accessory. To showcase the bridge itself, the three-dimensional production method is generally preferred, as it clearly demonstrates the size and elevation of the bridge. Specific methods are as follows:

1. Hierarchical Representation: Display the height, dimensions, and levels of the bridge using contour lines. During painting, the colors transition from light to dark from top to bottom, and shadow effects are created for a more realistic visual appearance.

2. Width Representation: In the manufacturing of bridges, visual errors can be utilized to convey the width, without the need for proportional reduction. Instead, certain widths can be intentionally enlarged to create a distinguishable visual difference in width.

3. Perspective Representation: Since we usually view models from above, the greenery strips and guardrails on both sides of the bridge should be made taller; otherwise, they are prone to be overlooked.

4. Fixed Model: Once the model is completed, it should be securely fastened to the base platform. This allows for partial application of adhesive, ensuring each segment is not overly long, and reinforcing the joints for stability.