Trimble Business Center: The Details

Trimble Business Center: The Details

Being a non-CAD program, the developers of Trimble Business Center were able to create something entirely new and change things they did not like about CAD, (things none of us like about CAD) with a fresh approach to data creation and manipulation. The roots of CAD have always been the creation of a 2D set of plans. The 3D first approach has become an advantage for TBC. Below are the things that make it function.

The Interface

Many of us CAD users are familiar with pull down and flyout menus. Trimble Business Center uses icons. Sometimes I forget where the command I want is, but you can bring up the command pane using F12 or find the icon in the ribbon bar where the command name and icon are listed. Here is a quick view of some of the commands you will find. As more are added, it is good to scroll through to see what you may be missing. When you want to be a real geek like me, run through all the commands and run them for practice. Updates happen without notice and become more user-friendly all the time.


When I want to streamline the data process, a well-written command will make life easier. However, automation of a process comes with a price and sometimes you get results you do not want. When trying something new or potentially harmful, do a save and give it a try. Trimble likes to build a left to right icon structure to streamline processes. My last article discussed this and the option of custom command ribbons. I will not repeat it here so check it out.

Enter Rockpile Solutions

The development team fixes bugs and creates new commands according to requests from users and for general improvement. Trimble released the language for creating macros and now anyone with a good understanding of programming languages can create their own. TML (Trimble Macro Language) will lead to new commands by savvy users but more importantly it has spawned a host of independent programmers that are doing it for us. Rockpile Solutions is one of those and certainly the strongest. Alan Sharpe formerly of Trimble is now at this company. They have a good relationship with Trimble so communication will eliminate duplication in effort. Some have stated they feel development will stall due to someone else doing the work. This is not the case with TBC’s development. The team at Trimble has a long list of advancements for an already mature platform. Do not be apprehensive but rather expect great things.

I like the fact that I can use one platform for everything from data to point clouds. The list of modules is extensive and now with the combination of geospatial and construction the depth is incredible. You may never need the full power of the program, but I cannot count how many times I needed to solve an issue and had the horsepower to do it quickly. This very thought is what should motivate you to scroll through the available commands to see what you are able to do.

Data Prep Components

All surfaces are made from 2D lines, 3D lines, and points. We need to get a CAD file useable from what was sent to us and get those three elements out the door and into the field. This starts with cleaning the project to make it perform well in the program. Project Cleanup can assist in getting things ready for data builds.

The forums have been buzzing with activity regarding Civil 3D files and TBC. The best way to get files from Civil 3D to TBC is to have C3D. The format is updated every three years and objects are best dealt with in native programs. Yes, it gets expensive but so does not having all the information you need. Autodesk makes a lot of proprietary formats, as does Trimble. That is the best way to get the functionality you need within the confines of your program and development.

There are a lot of tools in Project Cleanup that will help with CAD files that have the AECC objects converted to CAD objects. If you do not have the file in that configuration, there will be less information on the screen to work with.

The selections are self-explanatory. I will sometimes try a few different settings and undo the last file cleanup. In other words, I will uncheck some items that made a bigger mess than they fixed. Try various settings on your imports to get a feel for what you are looking at and why it may have gone sideways.

Now that we have a decent bunch of lines to work with, let us elevate things.

The Linestring

Any line that will be elevated or left 2D should become a linestring. CAD polylines can be used for 2D objects but make 3D items linestrings. There is a TML that does this, so it is easy. The reason for the linestring is the ability to manipulate it in a predictable manner. There are two separate sets of instructions that can be applied, horizontal and vertical. This takes a bit of getting used to but there are advantages.

A right-click on a linestring brings up a lot of options. I will open the Edit command and discuss the details of the object. The most important thing to note are the Horizontal and Vertical tabs. Here is how to view these tabs.

  • Horizontal change to a line will affect the Coordinate Geometry, (COGO) changing what you see on the plan view of the object. Straight segments and curves are made and changed here.
  • The Vertical tab affects the elevation of the line anywhere along the horizontal instructions.
  • Elevations can be changed in the middle of a long straight line in a place where there is no horizontal instruction. This gives you great flexibility.
  • There are other editing features for adding and removing segments and instructions.
  • You can also bring up a profile view to watch your vertical work in real time.

It takes a bit of time to work out a process here because there are many tools to choose from and learn their capabilities. Here is my method.

  1. Get the line connected and any loops removed. Sometimes I must follow the line with the cursor to verify this.
  2. Once I have a 2D line to work with, I make sure the color is good and it is on the right layer. I will often do the first round of work on the native CAD layer then move it to a 3D data layer. When I turn off the data layer, I find a lot of lines in the same location that could make a mess. It is not good to always rename an entire layer to a 3D layer; you may want to migrate individual lines.
  3. I now add the vertical component. I mentioned the profile view to aid in real time review. I will give the line a single elevation that is close to the middle height of what I am doing, this avoids the balance of a line at zero with your current work a lot higher. Set elevations with CAD text and/or the pdf under the linework.
  4. I will perform a review of this process in a video to help you better understand.

2D Lines

In the following point I am referencing contours that need to be included in a surface. They are at a single elevation making them 3D but we call them 2D. I have learned to live with it. TBC has some great tools for converting zero elevation lines to contours and they are easy to use. I try to get everything elevated then start breaking lines and deleting segments I do not need for a surface. This process seems to work best.


Many do not use points as much as they should. Points are easy to create and a big help when you want an exact place at a particular elevation. Here are the obvious and lesser known uses for points.

  • Center of rims for storm inlets
  • Top of covers for water and sanitary
  • Corners of wing walls, SES pads, and handicap ramps
  • Corners and direction change for pads and blowups
  • Points along flowline of storm and sanitary to aid in digging trenches
  • Striping layout
  • Light poles and common area equipment like benches and play structures
  • PC, PT and radius points for curb layout

Do not forget point collection in the field to return to the office for processing and storage.

  • Daily as-built shots for all phases of work
  • Utility lines and structure shots
  • Long occupation shots of the saw cut and connections for drive entries and deceleration lanes
  • Quick topo of retention areas to verify volume calculations

When combined, the three key items (2D lines, 3D lines, and points) become a surface for a takeoff or field data. Make sure each item is a separate task and are correct individually before combining to make a surface. It will relieve the process of errors.

Trimble Business Center: Under the Hood

Trimble Business Center: Under the Hood

As a user of most modern data platforms, I can easily use Trimble Business Center(TBC) to do most anything with ease. Being a non-AutoCAD program, the commands are different from CAD but achieve the same results. More on that later. First, I would like to discuss the advantages of the program as well as some of the tricks and tips I have learned along the way.

The Interface

As TBC matured, features and options have become easily available. The noun/verb selection and right click access have proven to be powerful.

Here is a list of options from a linestring right click:

  • Selection Explorer can help to group frequently selected items. It reduces the risk of not getting everything you need or too much.
  • Line Commands include Edit, Break Lines, Join Lines and Offset Line. They give immediate access to fixing issues related to the line(s) selected.
  • Variable Offset Line allows multiple instructions to a line and results new offsets. Think of a paving edge that can be made to form bottom and top of curb in one operation.
  • Add/Remove Surface Members is a way to take things in and out of a surface. I use this a lot for testing potential breaklines in problem areas.
  • Media Files are used to refer to an image of a point shot or relevant information that goes deeper than a line or node can.
  • Profile Viewer brings up a quick 3D of what the linestring is doing. It’s great for troubleshooting curb grades in a parking lot.

More Power

Trimble has reset icons to promote a left to right progression for a job. Countless others have created special toolbars and icon groups to deal with not missing a step. For years, I have had to work with clients that do not have a custom setup. I think it is unnecessary to go through these steps. Learn the commands and know their location and you will get what you need. Not every job needs all the commands. I see no big rush for producing these parlor tricks. My other issue is that commands are added and changed.

With my dismissal of workflow organization, how should you go about accomplishing a job? I think every job is different. Yes, there are threads that connect all work. 2D, 3D lines and points make up a TIN. The issue is getting there. CAD files come in different flavors and I may need to run down the rabbit hole in order to get a good-looking file to work with. Once I get things cleaned up, I can finish the data prep with the usual laundry list.

Biggest Advantage

I’m going to show this in a video, but the biggest advantage of TBC is the ability to try a breakline or surface change and update the model to see how things look. I have used a lot of different software and this has been a big game changer for the platform. Use it and leverage the power. This is a screenshot of the two windows open at the same time. Here the plan view and the 3D view show the new breakline and its effects on the surface. You can explore different results until you get what you want.

Interactive surface changes are a double edged sword. With power comes responsibility. Don’t get too cute – you might be messing with something the grader will blow through in a second. With that being said, when you need to get things changed in a hurry, accessing the 3D and plan view at the same time is important. The Surface Regeneration is usually set to auto. With big surfaces change that to “by user” to make a bunch of changes then regenerate the surface. You will save time and be able to see changes to an entire area without waiting for things to update.

The other thing I will do is add a bunch of breaklines to a job in plan view then use the Surface Members command to add or remove surface members to see what the lines are doing. Once you know what a breakline will do, remove some of them to reduce TIN density and make things cleaner.

File Transfer

The “get the file to the machine” process has always been a pain to me. Work orders and the rest are a lot of work but often necessary. I choose to do work orders when necessary for file creation. Meaning if I can make it in TBC commands, I will skip the process. With Earthworks, the process can get easier but it is still procedural.

With connected machines the work can get processed easily. We usually email files to the client’s office and they push them to the field as needed. Be careful with sending a lot of files out to operators. If you need to send one file a day, the file probably needs more work. The workers won’t know if what was done yesterday will be wrong today. An example would be a strip of pads in a subdivision. Somebody somewhere decided to raise that strip of pads by a couple of tenths. The grade checker goes out to verify the work done by the blade and finds things off. Make sure to document changes that affect the different types of work on the job with each new iteration. I use bullets and break out each trade, so you only need to pay attention to your work. Always use dates. Here is an example:

Site Changes 050120


  • Storm connection in NW corner has been updated to reflect surveyed elevations.
  • Waterline location changes in playground area.


  • Model now reflects 2 foot back of curb blowup for curb machine.
  • NE retention has been redesigned.
  • Lot berms have been added where required.

This information will make things in the field flow easier. It takes a few minutes in the office but makes the work in the dirt that much better. I am a big proponent of making things as easy as possible for the field. I came from there and it is a pain to type information for the rest of the crews on a small keyboard in the rain.

Layer Groups

AutoCAD users have always had an easy layer solution. TBC has made things better with easy layer group selection and sorting. When you want to move a layer to a group, highlight it in the View Filter Manager and right click to bring up the menu. Go to layer manager and change the group. I’ll go over this in the video but it’s a big deal to be able to grab the layer you want and switch layers around with this level of ease.

More Layer Tips

In the Layer Manager Box you can do even more things to make your life easier.

  • Rename the Layer to something you use in your CAD standards.
  • Change the color.
  • People often ignore line style. This is a good way to see what’s on a layer. Be sure to uncheck the Show all Lines as Solid in the bottom tool bar. Things can get slow panning and zooming when this setting is off so be careful with big files.
  • Line weight is a good way to highlight a layer to see what you have.
  • Protect keeps the layer from being deleted. This is useful when you get a template file set up and may not have populated one of your named layers. When you go to delete all unused layers, it will prevent these from deletion.
  • Display Priority keeps the layer in front or back when it overlaps a crossing line. I don’t use this much but it does help with dense CAD files.
  • Turn Layer printing on or off.
  • Delete a layer that is not protected and is empty.


We all have our routine upon reviewing a model done by someone else. The flags pane is one way to get a good snapshot of surface quality in TBC. The issue may be a mess or nothing depending on settings. Let’s look at what I mean.

Within the Project Settings/Computations/Surface is the Minimum Warning Distance setting. This is the factory setting of 7-thousandths of a foot. This means a flag will be thrown if two crossing 3D lines are outside that tolerance. That means a lot of jobs will have flags. Maybe dumb down the amount. I’ll leave the exact number to you and if you get it around a couple hundredths, you will be on track.

Yes, everybody builds perfect models. I do not have time to chase non-essential data down a rabbit hole to reduce the number of flags. Build a good surface, set a reasonable tolerance and chase those flags. You can then dial up the difficulty and see what you have. Don’t despair. Some jobs will have none no matter how tight you go. Enjoy the moment. Other jobs will need a ton of work to get right at high numbers. Choose your battles.

Using XML in Civil Construction

Using XML in Civil Construction

Extensible Markup Language (XML) is used throughout various coding and language platforms. In our field it’s used to produce and transfer data types for data prep and site construction. There are two versions of XML (1.0 and 1.1), and both will import into the current software used by civil professionals.


The basic format for XML was a good starting point for different industries. Autodesk started the widespread use of XML and import/export ability was added to more software as the code matured. Most development by commercial software vendors began to drop off after version 1.0 released in 2002. Version 1.1 is capable of additional and enhanced data but never got the desired traction.

Enter Carlson

Carlson Software of Maysville, Kentucky picked up the LandXML development process and produced version 2.0. The addition of textures and advanced data types was a good idea, but support from other platforms is lagging. I don’t think much more will happen as 2.0 was in draft as of 2014.

This image is an import of a LandXML file imported into Carlson’s Precision 3D. It includes textures, polylines and field-to-finish data such as the light poles seen along the road.

If this file were imported into another CAD program not supporting 2.0, the data would be limited to surface elements. In other words, a TIN surface with faces and breaklines would be generated without any additional data.

Understanding XML

XML documents, in a basic discussion, are made up of markup and content. We also need to look at the header section of an XML document, as it contains information we may need.

The XML Header

Importing a file into your software is usually not a big issue. Bringing in CAD and point files is routine. An XML import should be no different. Where there could be an issue is with the XML units and how they are interpreted by the software. Let’s look at an XML header.

  • We know the time and date the file was last saved
  • This is a version 2.0 file. Software that only reads 1.2 will still import information, just not all.
  • Know which units were used in the file. Know your software, some will not alert you of a unit mismatch. An example is provided in the corresponding video.
  • We have our first look at a tag with the unit(s) callout.

Markup and Content

Markup begins with < and ends with >. Between those constraints lies the content. It also encloses tags which can have content following. Anything that is not markup is content. That rule is not absolute but for civil XML files this will be what we see for the most part.

If we drill down in this section we see a surface named All Roads and Drives.  A Boundary will be created using the PntList3D points. Note the points are not comma delimited. They are Northing, Easting, and Elevation in a continous string seperated by a space.

In the next example, the screen shot calls out several boundaries and the connected points to make them. The boundaries are individual markup callouts because each 3D line encloses a different street. This will start and stop line generation for each street.

Here is a 3D view of drawn smaller boundaries. This also allows the closed line to be used in texture rendering and vertical adjustments.

In this file the surfaces that make up the roads are shown after the boundaries are written. The markup and content give you the type and ID of the TIN edge verticies as points. When the points are brought into the file, the TIN edges need to be called out so they form correctly. Shown are the end of the TIN points and the beginning of the point numbers that form the faces of the TIN.

The production of the TIN faces, (edges) continues to the end of the file.

Here are some things you will want to find out before importing an XML file. Be sure to make a copy of your file so edits can be undone if need be.

  • Most critical to review are the units. U.S. and International feet can cause problems. Note that International feet will be called “foot.”
  • Determine the software that produced the XML. This can come in handy. It doesn’t happen often, but files produced by different platforms don’t always import properly.
  • The XML file may contain coordinate system information letting you know how the job was set up.

  • Sometimes you may not want all the information provided in the file. You can clip out the tags and related elements you don’t want to import. I agree that all you need to do is delete the unwanted element. However, that unwanted element could be a huge surface or something that stops the file import and shuts down before the elements you want get put on the screen.
  • The original project name is often times included as a tag. This can help you verify dates and times to confirm you are working with the latest and greatest.

Why Use XML

The ease of producing, sharing, and importing XML files has made them the format of choice for data transfer. Large scan and photogrammetry surfaces can be easily digested by smaller office computers as opposed to point cloud formats.

With this ease, many people are transferring data in this format. I have outlined some steps for users to make file sharing easier. The knowledge gained by reviewing the raw XML in a viewer cannot be over emphasized. Take some time to look at files that have worked for you in addition to those that gave you issues.

When you get to know what’s in a file by reviewing it, your confidence will increase as well as the ability to verify sources and validity of files. Work with some files and contact me with any questions or issues you have.

What to Expect from Free Models

What to Expect from Free Models

Being offered a free model to work from could potentially save time. You may even think, “Why not?” In this post, I will discuss what’s entailed when working with free models and how to determine the best approach. Use this as a guide on how to look at a model you’re given and verify that it’s what you want. I’ve outlined a process to make it easy for you to verify if the data is ready for the field.

The Surface

Most of the time when you are offered a surface file, it’s something the engineer has produced. The quality of the surface file can range from “ready-to-go” to just useless. Two explanations could be the engineering firm may have built the surface file to be used in dirt calculations (takeoff surface) or created the file for a presentation. You will not want to use either one.

The Takeoff Surface

When providing numbers for permitting and dirt use, the engineer will make a surface file. For the purpose of a takeoff, it does not need to be exact. I have long stated that if you use your takeoff surface for data, you’re spending too much time on the takeoff. Another more important reason to be wary of an engineer’s takeoff surface is that it’s generally done at the first draft of the site. Comments from agencies, owners and the utility investigation will make changes to the plans that affect the surface rendering making the takeoff surface unrelated to the final plans.

The Presentation Surface

More engineers are using 3D design to produce better projects. A 3D model gives the stakeholders a better idea of what the finished job will look like. When the vertical components (e.g., buildings) are added, the improvements made to the appearance and function are easier to see and quick to update. As the design matures and gets in ground stage, 3D model updates usually stop and the focus switches to printed plan production and permitting. This is understandable and normal in the paper plan world we still live in. It will take many years for 3D models to become part of the plan submittal. In post approval, we see highway projects requiring 3D model submission for approval before paving. Civil sites are not there yet.

Surface Review

When you receive a surface file, there are several steps to confirm if it’s even worth loading in the rover. Time is money and it generally takes longer to review a surface file than to just start from scratch. To use a surface file, you’ll need to take the file apart and then reassemble it to verify it’s accurate. This will take almost double the time versus creating the file. At TOPS, we never use an engineer’s surface file for data. Our clients ask us to make it for them.   The following is the process I use to review a client surface file:

  • Inspect the file size. A surface file may be big because it represents a large area. I often see smaller surface files that are too dense and contain a lot of unneeded triangles that are hard to remove or filter.
  • Determine whether the surface is dense enough. If the triangles of the TIN are spaced too far to indicate correct details this affects accuracy. The file may get you through rough grade but a better one will be needed for finish.
  • Confirm the version. Many times the surface file is used for one of the purposes I outlined above and is an older version of the plans. We see this a lot. A quick way to tell is to look at the deltas on the plan revision box and see what type of changes happened since the file was prepared.

When the surface file has passed the above inspection, it’s time to review the quality of what you have. Be aware that any review and work you do short of a full build of the surface file can still mean problems. Be cautious.

Review Process

Always start with the most difficult parts of a surface file to model. I’ve outlined what to look for on the different project types, as well as, Field Model Requirements that can require models built for surfaces other than finish.

Civil Sites

  • Look for flat building pads and smooth sidewalks from there to the curbs.
  • Go to the parking lot and verify the storm rims are correct and look at the slopes to them. Are they smooth and in the correct direction?
  • Entrances and exits need to match up to the existing pavement. This is usually finalized in the field. Just look for big discrepancies.
  • Finally, review the retentions and landscaped areas. Check the volume of retention against the called-out requirements in the plans. Often these must change during the design process.

Field Model Requirements

  • Pad Blowups
  • Subgrade surfaces
  • Paving overbuilds for curb machines and base

Urban Streets and Subdivisions

  • Verify the COGO (Coordinate Geometry) of the centerlines.
  • Check the cross slopes of the streets.
  • Review the intersection quality. Verify the details shown match the plans. If there are no details present, look for water movement and drivability.
  • Verify the sidewalk and parkway (e.g., grass) areas that are critical to slope.
  • Confirm the 2D and 3D properties of lot and pad dimensions.

Field Model Requirements

  • Gut section (over-excavation of streets for fill by utility spoils)
  • Subgrade surface
  • Matching roadways into field shots taken at sawcut lines
  • Utility trenches


  • Verify horizontal and vertical alignments.
  • Confirm roadway width. Includes widening and intersections.
  • Review cross slope and super elevated curve transitions.

Field Model Requirements

  • Widening base for track grade
  • Subgrade surfaces
  • Non-conforming subgrades, this is where the subgrade is not parallel to the road surface or the break point of the subgrade is not at the road centerline.
  • Catch points that need to meet a field generated topo

It is possible to use a surface from an engineer as a basis measure of quality. However, when the smallest doubt arises, it is best to build it so you really know what you have. 

Enhanced Data: Highways

Enhanced Data: Highways

There is nothing more difficult, or rewarding, than seeing a highway job perform well from dirt work to paving. It takes years of experience to fully understand the process. My advice is to think differently about the approach. In upcoming blog posts, I will go over the different approaches available for both Trimble Business Center and Carlson. These will be high level overviews of the enhancements we use for basic road elements. If you are a beginner, we will offer resources to get you up to speed.

Horizontal Alignment

The coordinate geometry (COGO) of a road, or construction centerline, can either be a quick data entry job or an enduring nightmare. Here is an example of a curve table. When things aren’t working with the parameters entered, you will need to decide what figures to pursue and leave the rest to tweak as you go. Notice in this example the PI has two (2) different coordinates. It’s probably a typing error and a clue there is a problem ahead.       The following is a list of troubleshooting tips:

  • Enter the PC, PI, and PT coordinates and stations first. Then enter per the plan.
  • Adding the delta and the curve will help resolve calculation issues.
  • Recheck the other numbers to see how close you are to discover errors.
  • You may not need to contact the engineer if the numbers are close. However, close is relative and a lot of bad curves can affect the length of a centerline.
  • When the centerline is a median, or other non-road geometry, offsets will need to guide the actual construction. Be certain the horizontal and vertical alignments are correctly matched in all three dimensions.
  • Not all field software can handle Station Equations. The rover can decipher the information while the machine cannot. The short answer is to make two files and overlap the data a few hundred feet so the operator can make fewer file changes.

Vertical Alignment

Vertical alignments are generally not as challenging as horizontal alignments. The most common issue is reworking an asymmetrical vertical curve. I’ve listed some tips below:

  • A road starting mid-vertical curve with no information for the PVC can either be scaled or some math should be performed to get the curve right.
  • Rehab profiles sometimes come without instructions for the new alignment. Rules need to be applied to the existing profile to identify the adjustments. The reason is when there is a mill and fill requirement, a survey crew will stake and set up the road. This should be done electronically. It takes more work since the alignment needs to be drawn or imported from a profile view in CAD. (I will describe this process in more detail in a future article.)
  • When encountering bridges, it may be tempting to ignore the vertical curves to save time. Always include them to troubleshoot design issues during construction.
  • The vertical is not always in the center of the road. Worse yet, it can shift during the job. Don’t be concerned about stopping and starting a road job at a station where this occurs.

Super Elevated Curves

Super Elevated Curves are not hard to understand. Where they are challenging is getting the standard details to match the cross sections and super diagrams. The transitions can also cause confusion. There are conflicting opinions on guidelines to use for Super Elevated Curves dependent on the state or country we are working in. The following are the general guidelines that we use.

  • Normal Crown
  • Runout is the length of roadway needed to accomplish a change in the outside lane cross slope from normal rate to zero.
  • Runoff is the length of roadway needed to accomplish a change in the outside lane cross slope from zero to a high side crown slope (usually 2%). Some explanations stop there and use this term to detail the rest of the transition.
  • Runup is the length of roadway needed to go from a straight cross slope percentage to full super.
  • A lot of state formulas are produced by transitioning some fraction of the curve length, usually by thirds. This diagram displays basic rules that many DOTs follow.
  • Note the axis of rotation, it can change and shift when super curves are drawn by engineers using older software. Also be aware of an old job that’s received funding and plans have not been updated.


Now that we have a good foundation for making a corridor, it’s time to attach templates to the alignments. I build roads planimetrically with as many pieces and parts required to get it right. Planimetric roads are a combination of templates and plan based features.

  • Driving lanes always require templates; at least in areas without intersections.

  • Intersections will require more data.

Using planimetric roads is advantageous when working with data that goes into the field, and is used by data collectors like templates to slope stake. Be sure to make a file that skips the staking plan details. The machines are fine with a surface. However, white paving will depend on brand.

  • Drainage elements, like ditches and culverts, are sometimes only available in plan view. They generally take a lot of time to calculate and make into a template element. Best to drop them on the screen.
  • The further you go outside the roadway, the less you need that data on the road file. Consider putting retentions and other out of bounds work into a separate grading file.


The basics are done. We have a road on the screen. It is critical to remember that we are only building part of the information on the plans. Any questions can be answered in the standard details provided by the agency. This is an example of a partial list of the standard details for a job. Questions can come up because the plans that are printed, and sent to the field, are abbreviated. There is usually no need to print the standard drawings, but if needed the drawings are easy to pull up in the job trailer. Everything from super elevation calculations to guardrail shoulders are there. You may find the plans do not reflect the standards in some areas. There may be an oversight you will need to fix in the model before going to the field.


A lot of money is earned by meeting specs for a rideability bonus. All roading software has a way to check for the IRI, (International Roughness Index). This checks the current profile as drawn in the plans. We will often see a profile that is very close to the desired index. In other words, if the road exceeds the drawn profile by a small percentage, the index will not be met. In that case we will recommend a value engineering profile adjustment that will give the contractor a better chance of getting the bonus without affecting the road. Designers will often get a profile drawn by software, the algorithms do not take rideability into account; we are just offering the owner a chance to get a smoother ride for the user. Contractors will often get automated paving equipment paid for in a bonus depending on the size of the job. This reinforces my advice to be sure the driving lanes are produced with templates. Everything from widening to supers are better generated with templates for the software to correctly transition these and other elements.


New hardware used in the field has capabilities that can benefit from the enhanced data from software. Terramodel and other previous generation tools did an adequate job but the data was not robust enough to effectively drive modern grading and paving equipment. Make sure you are giving the field the best possible information. There is usually a lot of money riding on it.  

Carlson Software and Working with Surfaces

Carlson Software and Working with Surfaces

Carlson Software is a very adaptable tool. It can run standalone by using the IntelliCAD engine or as an add-on to AutoCAD and Civil 3D. At TOPS, we all run Carlson on top of Civil 3D. In my opinion, this provides a robust, versatile work platform.

In this blog post, I want to review some of the commands that make surface production and checking easier for advanced users of Carlson Software. These commands will be useful after creating a surface that includes 2D lines, 3D lines and points.

Surface Production

A surface can be a combination of 2D lines, 3D lines and points. The following outline is a good process to organize these elements:

Layer Naming

  • Use a layer naming convention system and stay with it. At TOPS, we use different conventions for clients based on their needs and history. Avoid confusion by standardizing your conventions.
  • Be sure that anything used in a surface starts with “3D” in the layer name. This helps simplify your convention so you don’t miss something on a surface that is not included in the model.
  • To go a step further, use a layer state with just the 3D layers to make sure you are building with all the correct elements.

Above is an example of the elements used in a surface.

Initial Surface Build

It’s common to initially build a surface by fixing the obvious mistakes in order to get an idea of what needs to happen to make it perform correctly. But, it’s important to remember that the surface must meet the engineer’s intent and make a moving blade cut good base for paving and buildings. Here’s a suggested process:

First, decide on the layers necessary to make an initial surface. Understand that you may not draw breaklines or added spot elevations at this stage.

Second, open the Triangulate and Contour command and populate the settings preferred for the surface. Here are some suggestions:

  • I like to initially see the faces to watch how things tin.
  • When doing an FG surface, try to make a boundary. Shrink wrap is okay to start a finished surface job or for an OG topo. Get a tight boundary before sending to the field.
  • Prefix Layers With Surface Name adds the name for the surface to all layers used. This is an efficient way to set all the layers in one spot.
  • You can adjust the Triangle Length but I prefer to let the program make the surface then add breaklines to control length.
  • Densify Breaklines is a great feature. It will add vertices at a specified interval, like densifying a polyline without the mess during production.

  • Draw contours for a check.
  • Run Contour Intervals at .1 feet to get an idea of surface integrity.
  • Don’t label contours for this step in the process.
  • The Selection tab allows you to pick the element type for the surface. This may help if you have un-needed element types residing on a data layer. It’s best to have layers with only types you want and not rely on selection types.

Here is the initial look at the surface:

Even with contours at a tenth of a foot, this surface does not have a lot of change in elevation. There are things we can do to make it perform better and it will be good to add breaklines in order to improve things.

When adding breaklines, the goal is to make the surface perform well when paved but more importantly it needs to work well with a grader blade that is tasked with smoothing things before paving.

This task takes practice and experimentation. There are no easy formulas to follow. Experiment and keep a good line of communication open with the field in order to get things working right.


After the first surface generation, I will add breaklines to the surface to make it look and work better. To apply this practice, I’ve outlined some general guidelines:

  • A breakline is nothing more than a 3D polyline. It can be generated by the software or added by the user. It’s named because it forms a grade break in a surface where it did not exist before.
  • People use too many breaklines. Don’t be afraid to try something and then delete it if you don’t like it. An example is included in the accompanying video.
  • Use the same rules for breaklines on the entire project. If you do work to make one island work, do the same changes to the others for consistency.

Here is a quick look at the same area shown before breaklines. The grading is now smoother and sharp grade changes have been eliminated.

In the video I will demonstrate breakline techniques that will get you on the right path to make the surface behave the way you want.

Working with Polylines

The most difficult part of data prep is working with 3D polylines. The hardest 3D lines to make are those associated with curbs in parking lots. We need to respect crossing contour lines and spots along a line representing the edge of paving or curb faces noted in the plans.

When a single line is properly made, we need to offset it to make other 3D lines in relation to the first. If we generate an edge of paving line, we will offset to make a curb bottom then top, and finally top back of curb.

Base 3D polyline creation

In this example, I will elevate the edge of pavement line, then move it in 3-dimensions to make the bottom face of curb and top back of curb.

The Edit Assign Polyline Elevations command now has a real-time profile view in the command to help you visualize the resulting line.

This project has contours at .25 feet. That presents its own set of problems because high and low breaks are seldom called out. This requires us to make those grade breaks. Below is a representation of one of those locations:

Contours are at 81 feet with no detail near them. Without additional work, the street would have a flat spot at the paving edges.

Always contour the site at .10 feet so that these flat spots will become obvious.

Once corrected, the surface will start to look better and perform well.

After creating a 3D line that represents what you are after, it’s now time to offset that line to get what you need. Open the Offset 3D Polyline command.

This command has great chops! There are a lot of variables in the radio buttons. I urge you to review and get used to them. For this requirement, I will use the multiple options.

The Change Layer option can be used for the other commands. There will be layer options in the next window.

With this window, we have a lot of options. I need to point some out for the best results. The Progressive Offsets checkbox takes the new line made in the next row. It makes the change to it and not just he original line being offset multiple times. We want to use that here.

We do not build curb this way. I am doing this as an example of duplicating a fill gutter and related curb elements. With the paramaters set, click OK and pick the lines you want to work with.

A quick look at the new lines in cross section show the gutter and curb details. This would not work for a grading file, this is just a good representation of what the command can do. We run the paving slope out to the face of curb then go to the top back of curb.

The command will also work for a quick pad stepdown or a blowup to get pad limits for slab prep.

The command is also useful for a simple entry road. The command will perform the change to the centerline on both sides giving you a quick roadway.

Another advantage to the command is that it will place the new lines on a layer of your choosing. At TOPS, we like to segregate 3D lines as much as possible and this command does it for us.

The Process

With the ability to create a surface and tools to adjust things, you now have the ability to get closer to what is required in the field. I say our work is 90% science and 10% art. It does not take years to get proficient at building data. However, do pay close attention to every step and the outcome of your actions to a surface. This will help you to get better faster. Focus on areas that need work initially and then step back to be sure everything works together as a good, performing surface.

Enhanced Data: Subdivisions

Enhanced Data: Subdivisions

Beyond the surface in a subdivision, there are things you can do to make your job easier. I will cover the more common tools we use to expedite planning in subdivision grading and paving jobs. I will also breakdown the improvements we’ve made beyond the simple site and linework.


Often there are several stages of dirt work within a subdivision. Don’t be afraid to create several surfaces for a site. Similarly, the details of the finished pad elevations, and even lot sizes, are not detailed due to the rush to get something out of the ground.

Starting with an erosion protection plan will establish several retention areas to contain site runoff during construction. These are usually basic and don’t require a lot of detail. Be sure to include any silt fencing and erosion barriers that are required in the initial work.


You can count on a lot of streets in a residential area. We have performed grading and paving data using many unique details that will help field crews. Here are a few of the models that we make:

Rough Grade Section

A great planning tool for dirt efficiency is a “gut section” model for streets. The idea is to do an over excavation of the streets so the spoils generated for utilities can stay there, and be used to get the road to subgrade in preparation for stone.

The above example shows the street to subgrade, cut straight across, ignoring the crown. We also went to 2-feet behind the curb so the curb machine can get better access. A model is built to street slopes as well so the subgrade and stone are set right.


One of the best things to do when establishing curb grades is to give the field extended information for more efficient outcomes. We have been building curb data that helps the field for years. Here are several of the ideas that make things easier for them.

Working with Curbs

Top back of curb (TBC) grades are the base for everything that happens for streets. The sidewalk is set from that elevation to the inside. The grade is used to set string line, or made into an alignment for a guided machine. When done correctly, the street base can be graded with a laser against the top of curb and paved, even with the gutter. The issue with a curb elevation line is it is exactly that, a razor thin line that changes quickly in elevation to the inside and 1.5-2% to the outside. Often times this gives us a slightly incorrect curb elevation that seemed correct but makes for an inconsistent road.

One of the best ways to provide solid TC elevations is to do an offset line, usually about 3-feet behind the back of curb, and make a surface reflecting that.

Here is a cross section showing the finished grade sidewalk section on the right and the flat TBC offset added to the right. A couple notes:

  • The name “Curb OS” appears on the screen because I named the linestring. That’s the reason I use naming for linestrings to verify their inclusion.
  • The sidewalk on the left has a 1.5% slope. The maximum slope for a sidewalk is 2%. We bring that down the half a percent to insure the slope never goes over the max.

The cross section of a curb relates to how things get worked out in a slip formed curb and nothing to do with grading. We will look at what the curb does as it’s placed and what we do with the subgrade.

When we grade a road, the above (in red) is how the surface is made. The cross slope of the road is 2%, and the slope of the gutter in this typical is 6.5%. If we were to respect the gutter slope, the grader would get confused and make a mess of things, as the tip of the blade got close to the grade break.

Keeping the slope at 2% gives a bit of stone for the curb machine to plane as it makes the pouring pass. The difficulty comes in understanding what happens when you dial down to get to subgrade.

In the above diagram I am dialed down to top of native. The subgrade needs to extend out for several reasons:

  • The original ground for the curb is not excavated.
  • There needs to be an offset to provide room for the curb machine.

To make this part of the job easier, be sure the TBC line is continuous so snapping and offsetting for grading is more efficient. When placing stone, be careful to get just enough under the curb to give the curb machine something to grab to but not so much as to waste a lot of material.

When you have made a surface that has the flat TBC area, be sure to include the finished grade surface so the sidewalks and parkway sections are correct.

Lots & Pads

Lot Marking

I have always wanted as much information as possible on a data collector to do my job. When it comes to marking out lots for grading sometimes you can get too much on the screen.

At the very least, you need to have the lot number and pad elevation. Here are some additions that may help in some jobs but can cause clutter if used at the same time:

  • Lot Dimensions are seldom necessary. Where we find them useful is for acre sized lots that are irregular and insure you are not grading somebody else’s property.
  • House layout lines can help to define driveways and lot grading details. They take a lot of memory due to the number of lines and detail. Clients may load and bring this on the screen late in the job.

This image is a good example of what you can put on a screen, and still keep your sanity. You would not have all the layers on at the same time. However, it is good to have grading, streets, and utilities together for convenience or for reference. Before exporting this to the data collector, I might change the lot number color from yellow to another color. It’s difficult to see in the light.

Pad Overbuilds

When you need to add block walls, or larger fences, to stepped pads an overbuild is usually required. This changes several things:

  • The lot line is now not the top or toe of the slope. It is necessary to maintain lot lines on your screen for clarity.
  • Some details call out overbuilds for a block wall then removing material later after it’s in. Watch the grading details closely.

This detail runs for over 50 pads in this subdivision. For this level of detail it is good to create a specific grading file for it.

The overbuild goes into the high lot 2-feet, after the wall goes in the bench and slopes are modeled to get drainage right.

Raking Pads

When a series of lots are vertically separated, usually by .3 feet or less, the grading plan calls for the pads to be sloped from the high pad to low. This is not a problem and makes the work go faster. Lot lines and pad compaction can suffer so be sure to detail these areas with good linework.


Lookout and walkout basements are an opportunity to use a lot more detail than flat pad sites. We have done everything from excavation pits and laybacks for walls to finished slopes outside the footprint to provide positive drainage between lots.

Each home site is an individual grading plan that has to be reviewed and data prepared properly. When the plan is designed well on the screen, guided excavators can make the basements quickly.


I have explained some drill down points that will help to improve accuracy in building subdivisions. The accompanying video goes over the information provided plus other details we use to improve the quality of this type of job. Included are some alternate approaches to lot and street design. Staying with design and translating that into practical models that increases efficiency is an ongoing task we take seriously.