Interactive engineering model
Roadway gutter spread wedge
See uniform or depressed-composite gutter spread and curb depth respond to flow, cross slopes, gutter width, depression, and Manning roughness.
Preparing the 3D model...
A cut-and-fill roadway section carries a triangular water wedge against the curb. The pavement plane, the depressed gutter pan, and the level free surface are drawn from one section, so the wedge always ends where the pavement rises to the solved spread. Controls switch between exact HEC-22 uniform and depressed-composite equations, a painted lane edge marks the 3.6 metre travel lane the spread is judged against, and the section is drawn at a stated vertical exaggeration.
Focus the 3D view and use the arrow keys to orbit, plus or minus to zoom, and Home to reset the view.
Text explanation and non-WebGL fallback
A cut-and-fill roadway section carries a triangular water wedge against the curb. The pavement plane, the depressed gutter pan, and the level free surface are drawn from one section, so the wedge always ends where the pavement rises to the solved spread. Controls switch between exact HEC-22 uniform and depressed-composite equations, a painted lane edge marks the 3.6 metre travel lane the spread is judged against, and the section is drawn at a stated vertical exaggeration.
The numeric controls and readouts remain usable if WebGL is unavailable. Drag or swipe the 3D view to orbit and use a wheel or pinch gesture to zoom. With the 3D view focused, use the arrow keys to orbit, plus or minus to zoom, and Home to reset. The complete numeric lesson is also keyboard-accessible in the adjacent controls and readouts. This model is an educational aid and does not replace applicable design standards or professional review.