Mass haul diagrams are a standard tool for roadway and linear earthwork bidding. The X axis is station along the alignment; the Y axis is cumulative net cut (positive) or fill (negative). Peaks represent surplus cut zones; valleys represent fill zones. Where the curve crosses zero, the project balances at that station.
From the diagram, the estimator identifies haul distances: free-haul (the contractor-included haul radius, typically 500-1,000 ft) and overhaul (haul beyond the free distance, billed as a separate unit price per station-yard).
Modern earthwork software (SiteWorx/OS, AGTEK) generates the mass haul diagram automatically from the TIN-based cut and fill. For manual bids, the diagram is plotted from station-by-station cross-section earthwork volumes.