My state agency commonly uses gutters with a 4% cross slope. The maximum superelevation rate is 7%. The gutter slope stays at 4% in this situation. Spread does not compute in this scenario because "A depressed gutter must have a Gutter Cross Slope that is equal to, or steeper than, Road Cross Slope". This should not be the case. Any spread section should be computable using HEC-22 methodologies.
| Civil Product Used | OpenRoads Designer, OpenRail Designer, OpenSite Designer |
This functionality was implemented in the 2025 release of the Civil products, where a new Gutter Shape of 'Composite' lets you define a series of lane widths and cross slopes, as shown in the attached screen capture.
Thank you for the update. This is a huge benefit! I worked on a project with a special composite gutter (V-shaped) that, with the addition of the road/shoulder slope all the gutter calculation software were unable to directly do the computation. We had to do those specially via spreadsheet. But this will be very helpful moving forward!