Text Box: Text Box: White Paper Autodesk Land Desktop

Bentley InRoads versus Autodesk Land Desktop Software: An Independent Comparison

Autodesk commissioned this review by Harry O. Ward, P.E. Mr. Ward is a Registered Professional Engineer and an Autodesk Authorized Consultant with more than 23 years of experience in civil engineering and computer-aided engineering, design, and drafting. He is well known in the industry for his pioneering efforts in computer animations, computer forensics and litigation, consulting, teaching, lectures, and publications. He has held the positions of Engineer, CADD Manager, and Director of IT for consulting and industrial firms and is currently the Vice President of OutSource Inc. Mr. Ward is a recurring author for several magazines including CADence and Point of Beginning and has been a member of the engineering faculty at George Mason University since 1997, where he teaches CEIE 290, “Engineering Computations and Design.” He was recently appointed to the Editorial Advisory Board of Point of Beginning magazine and was a featured speaker at Autodesk University^®.

The following report has been minimally edited for editorial and formatting consistency.

The software described below was reviewed comprehensively and from a workflow point of view. I analyzed the interface, algorithms, and functionality as a practicing engineer or surveyor would in an on-the-job fashion. The sections covered include the following:

· Project management, interface, and settings capabilities

· Primitive geometry and geometric layout capabilities

· Terrain modeling, terrain analysis abilities

· Alignment design and editing features

· Profiling and vertical alignment design and editing features

· Road design and cross-sectioning features

· Plan preparation

· Site design

· Hydrology, rainfall analysis, drainage, and utilities

· Retention pond design and pond routing

· Special features

My method of operation was to look at Bentley’s InRoads software (see www.bentley.com/transportation) in an objective fashion and to compare it to Autodesk^® Land Desktop 3 software.

Project Management, Interface, and Settings Capabilities

InRoads: The interface is a Windows^® compliant interface. The software interfaces to your chosen CAD system and keeps all data in a project database. Several state departments of transportation use this software and most of them use MicroStation^® as the CAD platform. Tutorial files are included with the installation of the software. A geodetic library is available that allows users to set their geographic coordinate system. Other features, such as units, coordinate state plane and UTM zones, project elevations, horizontal and vertical datums, coordinate labeling, and report formatting, are available as well. All of these can be edited any time during a project’s life. The data can be stored in the user’s choice of directory and it is capable of being run from a server.

Menus are arranged in a very compact, yet efficient fashion. Some of the major features that other companies offer as primary pulldown commands are simply submenus here. Toolbars do not appear by default but can be summoned easily. They can be customized by the user and recalled during the next working session automatically. The software uses a Symbology Manager that allows aesthetic changes to all generated features. Having a single location that controls all CAD standards is a strong one for enterprisewide organization. There is a Project Defaults dialog that allows control of all of the engineering and surveying settings that will guide computations.

Project management is performed via Open, New, Save, Saveas, Import, and Export commands. One item of particular interest is that a user can open any facet of another project and use it inside the current project. Although the components appear to be within a single project, they are nonetheless components. As a result they can be opened and used in any project. The most recently used (MRU) projects show up under the File pulldown. The XML data structure is supported by the software for sharing design information.

Other specialized software offerings within the InRoads suite include InRoads Bridge, InRoads Site, InRoads Survey, and InRoads Storm and Sanitary. These products offer solutions within their genre but maintain the same InRoads interface. Where the commands are related the exact same software is offered within each product, for example DTM commands and point generation. The interface has window panels and uses tabs to display the information about types of information. For instance, surfaces and related data are shown under the Surfaces tab, geometry data is shown under the Geometry tab, and drainage information for pipes, channels, culverts, and manholes are shown under the Drainage tab.

Autodesk Land Desktop: The interface is a Windows compliant interface. Land Desktop works inside the industry-standard AutoCAD 2002 CAD system. The main package is essentially for 2D project work plus terrain modeling and earthwork takeoffs. The Autodesk^® Civil Design and Autodesk^® Survey modules are add-ons and each has menus specific to their function with parts of Land Desktop integrated into them. The menus are customizable by the user and there is a facility to support this. Land Desktop is the leader in being able to develop an enterprisewide set of CADD standards. Project settings, drawing settings, and AutoCAD settings support the development of graphic objects for viewing and plotting. They can be centralized on a server or set on a machine-by-machine basis.

The external project database method is mature and flexible and has had feedback from thousands of customers over the past 10 years. XML is supported in Land Desktop 3. A feature evident throughout the software is the ability to access point data via the use of point filters. This allows for easy access to points that exist in either the CAD system drawing or the external project point database. Land Desktop comes with tutorial files and with the advent of Autodesk Map™ software being included, it has enormous capabilities to handle geodetic data and perform geodetic conversions. Land Desktop allows translations to ARC/INFO^®, ArcView^®, MapInfo^®, and MicroStation. The tools offered in Autodesk Map allow for drawing cleanup, GIS, and external database linking and querying. It also allows for super cross-referencing of huge spatial data sets consisting of graphic data, database data, and object data.

Land Desktop makes great use of the 3D Orbit command in AutoCAD for viewing data in 3D and in perspective. Several types of shading are built in and can remain shaded while working. Although CAiCE has many specialized commands for civil and survey functions, Land Desktop has a myriad of commands to achieve similar results.

Land Desktop can also track who logs into the drawing and what changes have been made to graphics through the Revision Additions command. It stores the information in a database that can be searched at a later time and interacts with the graphical elements to highlight modified data.

Benefits: Users benefit by Land Desktop’s integration with AutoCAD and Autodesk Map plus the object technology that Land Desktop uses. The InRoads product is quite strong in its design abilities but is fairly new to the AutoCAD environment.

Primitive Geometry and Geometric Layout Capabilities

InRoads: InRoads has a Geometry Style Manager that allows users to set up how points, lines, arcs, and spirals appear in the CAD system. Each style can be automatically applied to each roadway in the project, hence RoadA can display red points and red geometry while RoadB can have blue points and blue geometry. The aesthetics are tied to the roadway in question. InRoads allows points to be set using alignment data such as station/offset or North/East. Points can be set on most of the horizontal, vertical, and superelevated portions of roadways using design data or by graphical selection. Additionally points can be generated using Traverse commands which allow for angle directions, deflections, and curves. Points can be generated using alignment data both before the alignment begins and after it ends.

With InRoads Site, the geometry layout tools allow for parcels to be computed based on lot area or lot frontage. The software is designed to facilitate manipulation of the lots so that different scenarios can be explored. This is quite useful because lots are often changed for a myriad of reasons as the layout progresses. Lot Setback calculations are automated and right-of-way takings help in writing legal descriptions.

InRoads Survey allows users to transfer data from data collectors to the MicroStation or AutoCAD environment and has interactive data editing capabilities. It produces plot-ready graphics immediately upon reading the data. The Fieldbook Data Editor helps a user to interactively edit the raw survey data. Graphics update immediately, without reprocessing the raw data file. Survey data and attributes are feature-based and can be used to annotate each shot in the drawing automatically.

InRoads Survey allows traverse adjustments to be computed using the following industry-standard methods: least squares, traverse methods (which include Crandall, compass, and transit), and level (which adjusts elevations).

InRoads Bridge allows for the development of bridge projects. Structural components are developed through bridge-specific geometry commands such as Slab Fascia, Abutments, Piers, Girders (longitudinal framing), Framing (transverse framing), Substructures (which include pedestals and footings), and Slabs. There are also routines for creating “Verticals” which assign sectional data for prestressed I’s, U’s, boxes, plate girders, and standard steel sections. Drafting includes bridge deck routines and 3D extrusion commands for girders as well as typical bridge geometry layout.

Autodesk Land Desktop: Land Desktop has excellent land development geometry tools because the user can use the graphics commands in AutoCAD supplemented by well thought out routines in Land Desktop. It has many productive tools to build horizontal geometry. Some good examples include the following: users can draw lines with a “double snap” such as the Perpendicular and Tangent commands and they can use the Create Multiple command which allows for the creation of lines, arcs, and spirals from lines, arcs, and spirals. There are also many commands for settings points in 2D and 3D, and they are designed to operate the way a civil designer or surveyor needs them to. The method of prompting is also well thought out because the command sequence steps users in and then steps them out of the process.

The Autodesk Survey module has additional geometry commands that build traverses and sideshots in 2D or 3D and it can be done graphically or via dialog box entry. A batch file captures commands and allows for editing and playback.

The TDS Survey Link within the product allows for data collection from most of the data collectors in use. Links exist for those that remain proprietary. The methodology is simple and can be augmented by the Survey Command Line commands if they are added as notes.

Benefits of InRoads: Users benefit from InRoads’ excellent abilities to go beyond land development. The InRoads Bridge and InRail programs for bridge layout and railroad design set this series apart from other manufacturers.

Benefits of Land Desktop: Users benefit from the ability to reduce least-squares networked loops as well as a well-rounded set of commands designed for geometric layout in a CAD system. Curvilinear linework and points are easily created and modified and have a mature prompting sequence that will aid users in production. The Autodesk Survey add-on may be needed if users want the ability to traverse around a lot in a single command or if they want to be able to develop a nontangent curve from curve table data. The use of the Survey Command Line is a valuable tool for those creating geometry in Land Desktop, as it has built-in batch file ability and they can edited and run as needed.

Terrain Modeling, Terrain Analysis Abilities

InRoads: The terrain modeling abilities of the software are quite strong. It uses “Features” to define the source data for digital terrain model generation. A feature is a named set of points in a DTM. It can be one of five types: random, breakline, exterior boundary, interior boundary, or contour. Features are essentially just groups of DTM points—each group is given a name and assigned a feature style (feature styles control everything about how features gets displayed). The ability to identify different features by name, to select and edit them using filters, and to independently control their display characteristics are benefits of organizing a DTM into features.

The DTM TIN algorithm is based on Delauney's criteria, which creates small, triangular planes that define the terrain surface. This is typically the method most manufacturers use and is one where a triangle is created between the closest three points in the site. This command triangulates interior and exterior boundaries similar to breaklines, but these triangles are marked as deleted and are not used in any further processing. The deleted triangles still reside in memory, although they can no longer be accessed. This command checks for an exterior boundary that crosses back on itself as is sometimes likely when modeling roads. If the road has a tight radius, the exterior boundary may loop back on itself.

Triangulation allows for a Maximum Triangle Length parameter. The triangles are checked to determine if any side exceeds the Maximum Triangle Length value. If one does, the two neighboring triangles are marked as deleted and are not used in any further processing. This feature is useful in removing long, thin triangles at the edge of the surface. The software has facilities for handling very dense input data as well as a facility for “thinning” surface data using a series of three tests that can be initiated. Another nice feature is the ability to create inferred breaklines and points typically after contours are entered into the system. This will allow the surface to have a rolling effect that may mimic natural conditions better. Users can choose whether to check for crossing breaklines or mismatched elevations by turning on the Extended Data Checks option. This verification process checks to see if any breaklines cross, if breaklines cross at mismatched elevations, or if breaklines overlap. Triangulation can be done with this option turned off to speed up processing time.

Autodesk Land Desktop: The Terrain Explorer provides an excellent interface to the DTM and isopach data. It has a Windows feel to it. Generating a TIN is fast. Statistics are readily available for the data and condition of the data. The analysis tools are among the industry’s most robust because AutoCAD can provide many graphical functions for displaying vectors, fills, and quick graphics. The TIN editing is also powerful and has unique commands for automatic slope annotation, nondestructive breaklines, surface pasting, and object technology for quick sections, contouring, and labeling.

Benefits of InRoads: Users benefit from some neat features in the InRoads terrain modeling such as thinning, inferred breaklines, and maximum triangle lengths. Both programs use an Explorer style terrain interface and both use a topological breakdown of source data.

Benefits of Land Desktop: Users benefit from Land Desktop’s terrain abilities because of excellent TIN editing and TIN analysis. They benefit from the ability to use USGS DEM file data for large-scale terrain analysis. They suffer somewhat because often contours representing the tops and bottoms of hills and valleys are missing if there are no spot shots within the contour source data. For some reason, these “flat areas” often do not produce contours although they are accurately reflected in all TIN data computations for profiling, sections, and earthworks.

Alignment Design and Editing Features

InRoads: The InRoads software has been used by many state transportation agencies for years and has strong features along these lines. The main feature it has that many other manufacturers do not have is associative alignments. It supports spirals, user-defined typical sections with superelevation, and independent slope and ditch controls. On top of that it provides parametrically driven decision tables. Plan preparation routines then allow for plans, profiles, cross sections, contour maps, or shaded analytical models to be extracted to the user’s CAD standards. Directly supported functions include routines for road design, corridor design, road widening, and road resurfacing.

Roadway settings allow for both roadway (arc based) and railway (chord based) curvature computations. A strong assortment of other specialized geometry tools allow for roadway-based input for PI placement and editing, tangents placement and editing, and curvature placement and editing. A highly effective method for laying out horizontal road geometry is a concept called Fixed, Floating, or Free elements. When a user initiates the Apply by Components dialog box, computations start at the beginning of the alignment and continue working along the alignment, one component at a time. During this process prompts may appear for verification if more than one geometric solution is possible. Computations continue up the alignment, one component at a time, until all possible elements are computed. All solutions are displayed in temporary graphics and are written to the design file when you accept them if the Write lock is on.

Autodesk Land Desktop: Land Desktop uses vector graphics to define alignments. There is no way to develop alignments other than AutoCAD entities or Point Objects. Alignments are contained in an external database and can be freely used in any drawing at any time. Multiple users can work in the alignment database simultaneously, and record locking protects users from stepping on each other. Many commands exist that interact between the alignments and the development of other data such as alignment-based points and offsetting alignments.

Benefits: Users benefit by the maturity of Land Desktop’s networkability and free workflow style. InRoads users benefit from InRoads’ very strong roadway design features. It is used by many state transportation departments for their roadway design. Land Desktop does not readily handle the railway definition for curves where InRoads does.

Profiling and Vertical Alignment Design and Editing Features

InRoads: Existing profiles can be extracted from surface data or the user can select from a wide array of alternative entry methods. Superelevation diagrams can be output easily to show pertinent and often required data, such as left and right curb elevations that shift during the superelevation cycle. Vertical profiles can be accomplished similarly to horizontal alignments. A strong assortment of other specialized geometry tools allow for roadway-based input for vertical PI placement and editing, vertical tangents placement and editing, and vertical curvature placement and editing. A highly effective method for laying out vertical road geometry is a concept they call Fixed, Floating, or Free elements. When a user initiates the Apply by Components dialog box, computations start at the beginning of the alignment and continue working along the alignment, one component at a time. During this process prompts may appear for verification if more than one geometric solution is possible. Computations continue up the alignment, one component at a time, until all possible elements are computed. All solutions are displayed in temporary graphics and are written to the design file when you accept them if the Write lock is on.

In editing vertical alignments, those that are defined with vertical circles are computed differently than those defined with parabolas. The previous and next curve sets are not recomputed by point of vertical intersection and length of curve. Instead, these curve sets are recomputed by holding the point of vertical curvature (or point of vertical tangent) and the vertical circle’s radius.

Autodesk Land Desktop: The new Vertical Alignment Editor allows for very good interaction between the numeric dialog and the screen graphics. This is about as state-of-the-art as can be. All AASHTO parameters are built in, and the right mouse button produces a menu with many of the editing functions. The Calculator allows for experimentation and visuals are produced if the customer has a subscription to obtain the Vertical Alignment Extension. Graphics are updated automatically upon exiting the editing function.

Benefits: Users benefit by InRoads’ ability to take a different approach to vertical design in some areas. The vertical circles concept is interesting as is the Fixed, Floating, or Free concept. Land Desktop does not directly support asymmetrical vertical curves. Although Land Desktop has strong vertical editing abilities, many users can’t use them because they didn’t purchase the subscription to obtain extensions.

Road Design and Cross-Sectioning Features

InRoads: There are two facilities for roadway design, the Express Modeler and the Roadway Modeler for sophisticated conditions. The Express Modeler generates a 3D corridor model. The Express Modeler is intended for models that do not require the depth of information provided by Roadway Modeler. This command does not use any roadway definitions, so the only method of controlling side slopes is through the use of a single template. Furthermore, Express Modeler does not have any mechanism to incorporate independent control, superelevation, or right-of-ways. The Express Modeler command requires one template, a horizontal alignment, and an original surface. Normally, you would also use a vertical alignment to define the elevation of the roadway along the horizontal alignment. However, if you do not specify a vertical alignment, the Express Modeler command uses the elevations from the horizontal alignment itself. The Interval parameter controls the distance along the horizontal alignment between each application of the template.

The Roadway Modeler routine offers more flexibility in generating sophisticated corridor models. With Roadway Modeler, the user can control side-slope grades using a variety of means, incorporate independent horizontal and vertical controls and right-of-way definitions, and automatically superelevate template segments. The Express Modeler command does not provide any of these advanced features. The software uses typical sections defined through a very powerful numerical editor. All aesthetics can be set and changed in the editor, and template segments are added and modified here as well. As segments are created the user sees them in the preview. All possible conditions are allowed such as Dx, Dy, slope, offset, width, x, y, H/V and V/H. A mirroring facility is built in to allow selective mirroring of segments or templates. Superelevations can occur based on AASHTO methods as well as several international methods. Superelevation transitions are user-definable and can be based on a linear or nonlinear rate of change. InRoads uses a zone concept in its corridor templates that allows users to study related regions of the cross section. Design and superelevational criteria can be assigned to up to six zones on any template, each zone containing up to 255 segments.

Sidesloping can be governed by depth control, surface control, or from templates of fixed or transitioning segments aided by a parametric process called Decision Tables. Parameters can be applied with flexibility, such as in a bridge crossing where sidesloping is turned off between bridge abutments. The Roadway Modeler then assembles and processes the roadway data into a 3D Triangulated Topological Terrain Model (TTN) that assists in visualizing the final design and produces a surface that can be merged into existing ground.

Autodesk Land Desktop: Land Desktop has strong tools for single alignment based design. It is powerful enough for corridor design consisting of roads, tunnels, and aqueducts. It is a template-based system and allows for transitioning templates horizontally for lane widenings and contractions and intersection collapsing. It also allows for vertical transitions for sophisticated conditions such as bifurcated highways and nonstandard ditch design. The viewing and ability to edit sections is excellent and very fast. Superelevations are AASHTO based and allow for superelevation-based cross-sections to be automatically created. The software supports subassemblies, which allow users to assemble roadway components into final templates. Land Desktop makes nice use of point codes on templates to mark certain locations for use later in analysis and drafting. The software can automatically create surfaces from roadway data, tying out daylight contours nicely. It can also create 3D breaklines directly from roadway data, which makes it very easy to design cross-sections and cul-de-sacs.

Benefits: InRoads users benefit from the software’s very strong roadway design features. It is used by many state transportation agencies for their roadway design. Land Desktop users benefit from having many trained users due to the maturity and popularity of the software. Land Desktop has strong abilities to design roadways, but they are geared for land development. InRoads is designed to handle any type of road.

Plan Preparation

InRoads: A full array of reporting is available and complies with most state transportation agency requirements. There is a Plan and Profile sheet generator included that assembles construction plans for the roadway. It supports a P&P generator as well as a profile generator that allows for banks of profiles. The software is highly configurable for drafting purposes.

Autodesk Land Desktop: The Sheet Manager has been around for some time and is one of the industry’s most powerful such tools in that it pulls data directly from project databases to assemble plot sheets. It is highly customizable to meet customers’ CAD standards requirements. It can assemble P&P sheets, cross-section sheets, or single profile sheets.

Benefits: Users benefit by both systems in their abilities to produce construction plans. InRoads can generate banks of profiles where Land Desktop can only create one per sheet. Land Desktop is more likely to develop a finished product because the user has a much more customizable set of features that extract their information from the project databases rather than the graphics.

Site Design

InRoads: InRoads Site provides powerful site design, digital terrain modeling, and coordinate geometry tools to allow users to generate contours, profiles, cross sections, and cut-and-fill volumes. Two facilities are offered called Design Surface and Design Pad. They assist in laying out buildings and daylighting them and allowing interactive modifications to them. Automated routines allow for parking lot layout, building pad layout, and areas between buildings. The earthworks algorithm uses a loss-free, prismoidal method that uses every triangle in the surface data.

Autodesk Land Desktop: Very little on the market can compare to Land Desktop’s ability to design sites in 3D. The software has had the ability to do so for a long time and allows the user to use typical AutoCAD entities. The addition of the Grading Object and the powers it has for modification as a design changes is awesome. Land Desktop provides tools that interact with surface data and can extract elevations from any surface on the fly. Between the use of point objects, breaklines, and the grading object there is virtually nothing that can’t be accomplished. The site analysis routines augment this nicely.

Earthwork takeoffs are performed using one or more of the four methods supplied by Land Desktop: the grid method, the composite method, average end area sections, and prismoidal section based methods. Intersection design can occur in 3D and with only a handful of breaklines. They can be easily placed using the software’s exceptional breakline tools that automatically tie the two roadways together.

Benefits of Land Desktop: Users benefit by Land Desktop’s robust 3D tool set for site design and the multiple methods for performing earthworks. Land Desktop has had the philosophy that users should be working in 3D for over a decade. In this area the users need to catch up to the software’s capabilities. Users benefit from both programs ability to perform accurate earthworks takeoffs.

Hydrology, Rainfall Analysis, Drainage, and Utilities

InRoads: InRoads Storm & Sanitary offers advanced 3D modeling, design and analysis, drawing production, and data management capabilities for storm and sanitary networks. Included are comprehensive tools for rainfall computations, transport, and disposal. Both design and analysis for hydrology and hydraulic computations can be accomplished. The software allows users to lay out the drainage or utility system numerically or graphically, and based on geometry data it draws complete piping system with pipe and wall thicknesses. Lift stations and curved pipes are directly supported components of the utility which allows for a wide variety of systems to be analyzed. For computing rainfall analysis the modified rational and the SCS unit hydrograph methods are both supported. The modified rational method is used for rainfalls lasting longer than the time of concentration so that peak flow is observed. The peak runoff rate Q is calculated from the equation Q = CIA.

For sanitary systems the Compute Zone routine is used for computing inflows to the system. A well-thought-out table displays that is already populated with criteria and can be edited for residential, commercial, and industrial uses.

The software has a number of nice design/analysis tools such as the cover check option. This checks minimum pipe cover along the entire utility based on a user-defined parameter such as every 10 feet.

The drafting is strong for generating profiles and annotating them. Settings are preset and editable to get the pipe system to draw the way the user wants. A Plan and Profile sheet generator is included in this module similar to the road design. For hydrologic analysis the system generates the cross-section and profile data needed for the following programs: HEC-RAS, HEC-2, or WSPRO. Most typical parameters are extracted such as left and right overbanks, contractions, expansions, and Mannings factors. Good calculators exist for computing flow data in gutters, inlets, culverts, channels, and pipes. Flow equations supported are Manning’s and Darcy/Colebrook, which is a new one on the author. I found that it allows for the entry of a kinematic viscosity.

Autodesk Land Desktop: This software has good tools for watershed development and rainfall analysis. TR-55 based methods are routinely used for generating hydrographs. Land Desktop has good tools for storm, sanitary, and waterline drafting. The user can edit pipeline data more readily in this software than virtually anywhere else. Although Darcy-Weisback, Hazen-Williams, and Manning’s equations are available for design and analysis, the Manning’s equation seems most applicable. Because Land Desktop provides a VBA editor/compiler and the pipe database is in Microsoft Access, great potential exists for users to integrate their pipe sizing spreadsheets into Land Desktop. The Sheet Manager produces P&P sheets directly from the pipe database to meet users’ requirements.

Benefits of InRoads: Users benefit by InRoads’ ability to design storm and sanitary systems, where sanitary is missing from Land Desktop. InRoads supports lift stations, curved pipes, HEC-RAS, WSPRO, and gutter and inlet analysis, where Land Desktop doesn’t. The InRoads cover checking is also a benefit to their users.

Benefits of Land Desktop: Land Desktop has excellent graphical previews of the hydraulic results in its calculators. You do not need a PhD in hydraulics to understand what happens in Land Desktop when the flowrate is increased or decreased as graphics preview the results. Land Desktop stores all of the pipeline data in Microsoft Access databases that are conducive to access by Visual Basic for customizing reports. Land Desktop has the Visual Basic Editor and compiler built in.

Retention Pond Design and Pond Routing

CAiCE: Basin delineation and subbasins can be created. DTM-based flow vectors help define these. Basins are generated based on the flow vectors. Then the hydrology editor is used to grab this basin, to which impervious conditions can be added or edited. It uses the q=cia method, computing the Tc times and the idf tables to compute runoff. Open channel analysis is supported via ditch analysis. It is also hec-22 based. It also supports a variety of ditch lining conditions. It reports flow conditions and shear stress locations for erosion and bend protection. Pre- and post-developed hydrographs can be generated using scs methods, rational or manually entered. The initial water surface can be entered for wet ponds. Tailwater conditions can be specified. Control structures can be developed using a wide variety of outlet devices. Report generation is done using HTML reports and includes hec-22 storm drain and hgl losses. Aside from the above, I couldn’t find any specific pond routing routines.

Autodesk Land Desktop: Land Desktop has the best interactive features for pond design and analysis in the business. A pond can be built in 3D using such criteria as the storage capacity needed for the pond, depth of pond, pond templates, and more. Once the pond is created, its characteristics can be sent directly into the pond routing and sizing functions. They use the Storage Indication Method for routing and Detention Basin Storage method for sizing ponds. Outlet structures can be developed and set to required elevations. They can further be turned on or off to simulate a variety of conditions. TR-55 and TR-20 are supplied. A variety of hydrograph formats are supported and created. HEC-II card generation is also supported but lacks input for sophisticated conditions.

Benefits: Users benefit by using Land Desktop because of the interactiveness of the software between pond design and pond analysis. Land Desktop can develop a pond with real life bottom conditions such as low flow channels and forebays. InRoads users will benefit by its use of HEC-22, but it seems limited in its pond routing abilities.

Special Features

InRoads: Bentley offers the InRail module for rail design and the data meshes with the other InRoads products. InRail provides geometry tools, site and track design abilities, and routines for rail manufacturing, reporting, viewing, and annotation. Users can quickly place turnouts and frogs as geometry from a library of standards or from custom definitions. These can be moved, edited, reported on, and annotated during the project work. InRail offers advanced functionality such as track points, regression analysis, slew diagrams, a track editor, and cant/superelevation.

Another module offered by Bentley is InRoads Bridge. It offers geometry layout of bridges, for complex bridge geometry or simple span bridges. The work is typically done in 3D from which drawings and reports can be extracted. The software calculates all information from the roadway’s geometric and digital terrain models, not from CAD graphics since different CAD programs have different levels of drafting accuracy. A variety of girder types including plate girders can be laid out with options to configure them as needed. The design can then be adjusted to accommodate haunch, curvature, camber, and deflections.

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