Super alignments are a powerful string type in 12d Model that allows horizontal and vertical geometry to be managed independently within a single string. Unlike a standard super string, a super alignment can contain its own horizontal geometry—such as straights, curves and transitions—and vertical geometry, including grades and vertical curves. This makes super alignments particularly useful for design applications where both the plan and profile need to be controlled independently while remaining linked through chainage. In 12d Model, super alignments are commonly used for road and rail design, airport runways and taxiways, drainage channels, and other civil infrastructure projects.
One method for creating a super alignment is the IP (Intersection Point) method, which builds the horizontal alignment by establishing horizontal intersection points (IPs). The initial straights are defined through the IPs, after which curve radii and, where required, transitions or spirals can be added. The vertical component can then be developed separately using vertical intersection points (VIPs), grades and vertical curves. This approach gives designers greater flexibility when refining an alignment, including the ability to insert specific grades over a set distance, change existing grades, add vertical curves, or position IPs precisely using coordinates and CAD snaps.
Creating a super alignment in 12d Model starts from Strings > Super Alignment > Create a Super Alignment, where users can define properties such as the string name, model, colour, starting chainage, labelling style and whether the alignment should be closed. Advanced settings also allow a super alignment to be configured as a pipe or culvert, with options for its justification and size. During editing, dedicated super alignment tools can be used to add or move IPs, insert curves, extend geometry, adjust grades and refine the horizontal and vertical design. These specialised tools are important because super alignments are a unique string type and have their own editing functions.
Existing strings can also be converted into super alignments, making the workflow useful when working with survey or CAD data. Individual strings can be converted through Strings > Convert > Super Alignment, while multiple strings can be processed through Utilities > A to G > Convert > Super Alignments. When bringing CAD geometry into 12d Model, separate lines and arcs can first be joined into a single string using the Head to Tail utility before conversion. The conversion can then be performed using either the IP or Element method. Once converted, the dedicated super alignment tools can be used to apply labelling styles and further edit the alignment, providing a practical workflow for turning existing design geometry into a fully editable horizontal and vertical alignment in 12d Model.
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