Bridge fire protection is an important part of bridge engineering. It is necessary to classify bridge fire protection into different levels in order to ensure the safety of bridges and the people who use them.

Bridge fire protection can be divided into four levels: Level 1, Level 2, Level 3, and Level 4.

Level 1 fire protection is the most basic level of protection and is designed to protect the bridge from small fires. This level of protection includes fire-resistant materials, such as steel, concrete, and other materials that can resist fire.

Level 2 fire protection is designed to protect the bridge from moderate fires. This level of protection includes fire-resistant materials, such as steel, concrete, and other materials that can resist fire, as well as fire-resistant coatings and fire-resistant insulation.

Level 3 fire protection is designed to protect the bridge from large fires. This level of protection includes fire-resistant materials, such as steel, concrete, and other materials that can resist fire, as well as fire-resistant coatings, fire-resistant insulation, and fire-resistant barriers.

Level 4 fire protection is the highest level of protection and is designed to protect the bridge from extreme fires. This level of protection includes fire-resistant materials, such as steel, concrete, and other materials that can resist fire, as well as fire-resistant coatings, fire-resistant insulation, fire-resistant barriers, and fire-resistant sprinkler systems.

By classifying bridge fire protection into different levels, engineers can ensure that bridges are adequately protected from fires of varying sizes. This helps to ensure the safety of bridges and the people who use them.