About 20 years ago, I saw a program called DCA. I got excited because I recognized that it brought something different to the engineer and that it would be a huge success. The company became Softdesk and finally merged with Autodesk. The program was not exciting because it was well done. The digital terrain modeling was very buggy, but users could profile and cross-section it. Users could do a lot of calculating and plotting almost at once instead of the long processes that had to be done before and produce a plan/profile sheet in minutes instead of hours.


Essence of Good Programming

Well, I have that sense of excitement once again. I believe that I have again seen something different: Infrasoft's MXROAD. I believe it will be a great success. For those who have been designing roads, I do not have to write how much time, training and experience it takes, not just to design the road, but also to learn to use the tools of a software program to perform the design.

Even my earliest reviews stressed that good programming for surveyors (and engineers) should allow them to concentrate on exercising their professional judgement, rather than force them to become computer experts. A surveyor standing in the middle of traffic with a dog chewing on his or her pant leg doesn't have time to worry about how a program works.

Whether you are designing a county road or an 8-lane superhighway, the algorithms for the hundreds of operations are the same and the computer implementation of the algorithms is very similar. What is so special about MXROAD is its properly designed database and properly designed graphical user interface (GUI).

Those fancy words mean that you can manipulate your model using a mouse. As you manipulate the model, the data sheets (database) containing all the information of the design are automatically updated.

Infrasoft says that the secret of its success is "string technology." The basic string is a break in grade or break line such as a flow line or ridge. Improvements are nearly all break lines, usually with a fixed relation to one another (top back of curb, top face of curb, gutter flow line, edge of gutter and so forth). There are also many other strings for every type, such as property line, which is a 2D line. Each different kind of string is stored in a database with appropriate information for each type.

Designing a Road

To design a road in MXROAD, you have to start with a survey. You can create a surface with a single command. Once there is a triangulated network of the surface, you are ready to begin designing your road.

Each road design begins with a master string, in the database of which is stored all the pertinent data (beginning coordinates, orientation, station, PIs, curve and spiral data and so forth). You can put in the design road centerline by the usual method of defining PIs. You can move them around, put in curves and perform all of the usual functions. You can also define the centerline by selecting existing elements (such as lines, curves and spirals) and create the necessary links by simply selecting the elements to join. If you pre-select the curve data, MXROAD will put in the curves automatically as you add the PIs. You can edit them at any time. You can move PIs, add them or delete them at any time. Curves and spirals will be automatically recalculated and displayed. As always, everything is visible.

Once you have the horizontal alignment where you want it, you can go directly to profile view and design the vertical alignment. The ground profile of the horizontal alignment comes up automatically. You can add, move and delete PVIs as needed. You can lock on the surface so that the PVIs have not only x and y but also z. You can meet any elevation or grade requirements. The vertical curves will be put in automatically by the criteria you set. They can be edited at any time by either using the mouse to pick and drag or changing the data in the database, which will be displayed for editing when the curve is picked. There is a lot of flexibility and power in both the horizontal and vertical design, and everything is always visible.

Road Design Templates

Once the centerline is complete, the fun begins. The road is designed in stages, first the centerline, then the roadway and then the shoulder. There are 102 templates to choose from, which are displayed in 3D. Figure 1 shows three of the 102 templates. The center one has been selected. Strings are created at each point in the template. The roadway surface is designed. If the one you need is not there, you can take the closest one, modify it to whatever standard you want to meet, and save it under another name. You can create a whole different set of standards just by picking and dragging with your mouse the various points in the template. Now these templates are different. They are really a collection of string creators, which attach each string in a fixed relation to the centerline. The templates do not have to be symmetrical. Once you have established a roadway, you can automatically add superelevations by selecting AASHTO standards for the top speed. The software contains powerful editing commands to modify the superelevations to meet any criteria. Figure 2 shows the selection of pivot points. Notice that one selection is grayed out because it is not appropriate for the roadway we are using, a very useful feature.


After the roadway is attached, you can address intersections, road widening, and on and off ramps. I took a model not in the demo and designed my centerline over an existing road. I had to copy the existing road strings into my design model and rename them to coincide with the MX convention. It took two commands: copy string and rename string. Then I was ready to use the powerful intersection design feature. First, you select the road edges and the radius you want on the curb return, and the design tool appears to draw the curb return. What it is actually doing is creating a 3D string and the backup database record. You can then "tidy" up the intersection, and the feature deletes the unwanted string parts and joins the curb return to the road edge so that they are one string. One of the more powerful design programs is the one that places traffic islands in the turning lane. It is a combination of 3D strings that precisely fit the curb return. Figure 3 shows the 3D model of a 6-lane divided highway, starting at an existing road, designed in 30 minutes by an absolute novice user (me). I wanted to show the 3D traffic islands with curb and gutter created with a single command. I have added a shoulder and a side slope to existing ground, which I will discuss below. The next step is to analyze the design for flat spots where water will stand, to be marked with the analysis tool. You can also fill the design with flow arrows so you can see where the water will flow. If you edit the flow line, horizontal and profile views are displayed on one screen. With the mouse, you can drag the profile up or down until you have eliminated the flat spot or moved the low points to the position of catch basins. Every mouse movement updates the design and the database. In fact, in this program, whatever you need at any given moment is always on the screen.

Creating Shoulders

Once the roadway surface is completed, the shoulders are created in much the same way. There are 15 shoulder templates in my copy, but they are as easy to customize as the roadway templates. Once you select the template, it adds the necessary strings to complete the surface design. To merge the design with the existing ground, go into the earthwork wizard and select the design of the side-slopes (another 15 or so choices). You can now create a DTM, contour it and even give a photo-realistic isometric picture as seen in Figure 4.

The power does not stop there. You can create cross-sections by a single command. Then you can edit them. When you edit a cross-section, you update the entire string in the design database. You can use your mouse to move a point or a group of points, or you can move points on all cross-sections by using the boundary command. In Figure 4, there is a fence that is encroaching on the design. You can use the fence string to limit the edge of the design so that it does not overlap the fence. You can see that the design has been pulled in so as not to overlap the fence (represented by an orangish line). I took Figure 4 from the demo disk because I have not been able to find a Windows NT 4.0 driver for my Paradise graphics card that will show more than 16 colors (Figure 4 was taken in Windows 95 using 65 million colors). Note that Figure 4 shows MXROAD running in MicroStation, whereas the other figures show MXROAD running in AutoCAD.

Pavement design is as easy, flexible and powerful as alignment and cross-section design. So are sub-grade and sub-sub-grade designs. Once pavement design has been completed, you can apply it to all of the cross-sections. You can use the cross-section editor to apply different styles of pavement anywhere along a road. You can then get a report of volumes of each of the materials necessary for your design.

You can then check your entire design against AASHTO standards or any set of standards that you specify. You can store state standards, DOT standards or your own firm's standards and check the entire project automatically. The report will show all discrepancies in red so that you can address them easily. Infrasoft has taken most of the drudgery out of road design and nearly all the drudgery out of learning the design program. You can now easily address all of those special little problems that creep up in every project.

Infrasoft also provides a drawing production tool. I used it to create 15 plot-ready Plan and Profile sheets in about five minutes. I did cheat on one thing—I used an AutoCAD template from the Colorado DOT. Otherwise, the drawing production tool created the sheets automatically. I have never created them so quickly with so little input before.

Demo CD Available

Infrasoft offers a demo CD for MXROAD, which I strongly recommend. It will take about one hour to view all of it, but it can easily be viewed in 5-minute segments. It will give you more of a hands-on taste than I can give you in this short review. In fact, if this review does nothing more than get you to order and watch the demo CD, I will consider it a success.

Infrasoft also offers MXRAIL (for the design of railroads) and MXRENEW (for pavement renewal). All MX programs are available in a stand-alone Windows NT version or embedded in CAD programs such as AutoCAD Land Development Desktop, AutoCAD and MicroStation. Infrasoft also maintains a website at, where you can find product information, contact information, updates and news.


Joe Bell is owner of SCJ GPS/GIS Consultants in Las Cruces, New Mexico, and the Software Review Editor for the magazine.

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