(This functionality is available
with the Profiles and Design module)
The design concept of LISCAD is comprised of a combination of string design and cross section template design, drawing from the best of which each has to offer. The user can use either approach depending upon which is considered to be the most practical at the time. In most cases the user will incorporate a combination of both techniques.
Most designs will generally commence with one or more horizontal alignments and possibly secondary alignments related to the primary alignments. The user may then choose to create long sections along these alignments and create a vertical design. This will then control the alignment in three dimensions.
Generic templates can be designed and saved to a template library file that can be used at a later stage on various data sets. Templates can be a simple set of instructions to define the shape of a design section, or they can be more complex with conditional tests on surfaces.
Template conditions are based upon intersecting surfaces. An intersecting surface can be represented by an alignment, a long section or a cross section set. Alignment surfaces should be thought of as a vertical plane passing through the alignment. Probe lines can test for alignment surfaces in any direction except vertically. Long section surfaces should be thought of as a horizontal plane passing through the long section. Probe lines can test for long section surfaces in any direction except horizontally. Cross section sets define the surface at each section marker and probe lines can test for intersection in any direction.
Decisions as to what the template will do are always based upon whether there is an intersection with a surface or not. This will result in the final design surface always following a single path, although the result can be different from section to section depending upon the conditions encountered.
After designing your alignments and templates it is necessary to create a Template Implementation Set. The Template Implementation Set is used to attach the desired templates to either the control long section or cross section set. It can also be used to make progressive changes to the templates to cater for road widening or superelevation etc.
When a Template Implementation Set is applied a new design cross section set is created. This cross section set is exactly the same as any other cross section set and individual cross sections can be edited to make any changes that may be considered necessary.
After the design cross sections have been finalised it is possible to transfer the cross sections into the plan view so that the full effect of the design can be seen and also to allow the design information to be output to a data recorder for setout. When transferring to plan the cross sections are strung together based upon the codes in the cross section. At the same time any existing information underlying the new design can be disabled, enabling a model to be formed which integrates the new design into the existing surface.