What is a mass diagram used for in highway design?

A mass diagram is a graphical representation that illustrates cumulative cuts and fills along a highway alignment. It serves as an essential tool in highway design, as it allows engineers and planners to visualize how much material needs to be excavated (cut) or added (fill) along different sections of the road. This information is crucial for achieving proper road geometry, estimating earthwork quantities, and ensuring effective drainage and stability of the road design.

In creating the mass diagram, the cumulative quantities of material are plotted against the length of the highway, making it easier to identify sections where there's significant excavation or filling required. This helps inform construction practices and overall project cost estimations.

Understanding the concept of cuts and fills is vital in the planning and design phase because excessive cuts or fills can lead to increased costs, longer construction times, and potential environmental impacts, making the mass diagram an invaluable part of the overall design process.