Poor drainage is a safety issue; without proper drainage and water flow, roads and railways can turn into hazardous places. Culverts and bridges help guide water under and away from transportation infrastructure, but just because their functions are similar doesn’t mean they’re the same. So, what are the differences between culverts and bridges, and is one better?
What Is a Culvert?
As mentioned, culverts allow water to pass under transportation infrastructures such as roads, highways, and railroads. They prevent flooding and erosion while allowing water to flow and can protect farming and engineering sites. In doing so, they also protect local wildlife by allowing water to flow safely away, not only from roads but from trees and rivers that can overwhelm the environment. There are also many different culverts, such as arch, pipe, box, and even bridge culverts.
What Is the Difference Between a Culvert and a Bridge?
While they both allow traffic to pass over water safely, their function, size, maximum weight load, and design are very different. Culverts are embedded within the soil and will bear the weight of passing vehicles overhead, whereas bridges will have support structures to hold their own weight and the weight of traffic. Additionally, bridges can be much larger than a culvert and can go well beyond 120 meters in length.
Ultimately, the main difference between a culvert and a bridge is their designs’ original functions. A bridge’s design function is to facilitate a transportation route, while a culvert is simply designed to redirect water.
Which One Is the Better Drainage Option?
Culverts can be beneficial in a variety of situations, as they’re much easier to build than bridges and can perform a similar function. If the waterway is less than 20 feet, it’s more economically viable and faster to build a culvert. They can also be used temporarily for construction sites. Additionally, culverts are easier to fix and can be fixed through non-disruptive means, known as trenchless culvert rehabilitation.
A bridge is best suited for long-term traffic and large waterways, such as major rivers or waterways over 20 feet. The more obvious benefit is that they can pass over more than just water, such as ravines, rocky terrain, and other hurdles that may block the flow of traffic.
In truth, one is not necessarily better, as it all depends on the needs and the size of the individual project.