Lot Network Road Network

This command develops the linework, geometry and labeling for subdivision, commercial and industrial sites by using the familiar Road Network interface and pre-defined settings. The program docks a dialog on the left of the screen identifying the geometry settings and all road files and leaves an active CAD screen and command line. You can save drawings and run virtually any standard AutoCAD command while within the docked dialog. Once you identify centerlines for the road network, the program detects intersections and end segments suitable for cul-de-sacs, and through input of design parameters for offset criteria, cul-de-sac dimensions and intersection transitions, the program will process the complete geometry layout, with output options including creating Lot files for later reference and a variety of labeling options for such items as Areas, Distances and Bearings. The road network settings are saved in a .RDN file.
Before running the Road Network, use the following procedure to setup the lot labeling settings and site boundary. Click the Lot Network Settings button. Note that you can use the Area/Layout Menu pulldown to access these commands as well. Select or create a lot network settings file. Next, select the Set Boundary icon. Select a closed polyline for the boundary around your site. Next select the Road Network icon. When prompted, select the .RDN file from the Existing tab. This is where the centerlines involved for the subdivision will be defined and added to the Road Name area of the panel. These centerlines are standard Carlson .CL files. Click a centerline and choose Edit. If a CRD file is requested choose or create a .CRD file. The Edit Road dialog appears. The centerline can be selected here and these centerlines can be edited on the fly if needed. For ROW Offsets, we are using the Row-OFF-a.Row file. Click Edit. The ROW offsets dialog displays. Use the defaults of 45’ left and right and note that additional graphics can be automatically generated by hitting Add and entering additional values, names and layers. Hit Exit.

Note also that Optional Input files can be attached to the process for roadway widenings based on the standard Carlson Road design tools of the same name. This is where a polyline indicating where the roadway template ID’s should be tapered or widened is developed into a Centerline file and attached to the roadway template involved. Refer to the Road Design documentation for this information. Hit OK to close the Edit Road dialog. These settings can be set and altered for each road in the network.

Next click on one of the intersections you may have and select Edit Intersection. In the Edit Intersection dialog, the intersection’s radii can be set. Click on the Front Left or Front Right to verify this. Hit OK when ready.
The program can also develop cul-de-sacs for the subdivision, although this example doesn’t require one. To see how it works, click Add under Cul-de-sac’s area of the panel. The Select Road for Cul-de-sac dialog appears. Select the road for the Cul-de-sac and the Edit Cul-de-sac dialog opens. Then as shown in the figure, choose whether the cul-de-sac occurs at the beginning or ending of the roadway, provide a cul-de-sac radius and filet radius and any other criteria to develop the graphics as desired. Since we do not have a cul-de-sac in this example we will skip this step.
Next select Settings at the bottom of the Road Network panel. The Radius is the default for new intersections. The radius for any existing intersection can be modified by selecting the intersection in the list and picking the Edit button. The Create Lots setting draws linework for lots for the specified geometry parameters. Otherwise, only the ROW polylines are drawn.
Use a radius of 25.0 and turn on the Create Lots toggle and click Settings. Set the values as shown in the Create Lot Settings dialog below. Then hit OK and OK to exit.Prompt For Each Area: This option will pause to prompt for the target area as each lot is created.
Target Lot Area: The new lots will have this area +/- the Lot Area Tolerance under Lot Network Setting plus any effect from handling the Remainder.
Minimum Frontage: Controls the minimum lot perimeter length along the ROW.
Use Setback For Minimum Frontage: This option bases the Min Frontage check at the specified Frontage Setback from the ROW.
Minimum Lot Depth: This setting is the min distance from the ROW to the back of the lot for the lot side lines.
Maximum Lot Depth: This setting is the max distance from the ROW to the back of the lot for the lot side lines.
Minimum Back Distance: This setting is the min distance along the back of the lot perimeter between the two lot side lines.
Interior/Back Reduce Offset: For interior boundaries generated by the program between lots, this option reduces the number boundary vertices. A vertex is removed if it doesn't affect the boundary by more than the specified offset amount. This method is similar to the Reduce Polyline Vertices command.
Edge Method: The lot sides can be created perpendicular to the frontage ROW, back boundary or at a specific angle.
Remainder: This option determines how to handle any remaining area that is less than the target area after fitting as many lots as possible. The Create Separate End Lot will make a lot with this remainder area. The Apply Equally to All Lots will spread the extra area to all the lots. The Add To Last Lot will add the remainder to the last lot created making it larger than the target area. The Create Back Lot Edge makes a back lot edge that meets the target area at min frontage.
Lot Type: Sets the lot type for the new lots.
Check Building Placement: Checks that the building footprints fit within the lots for the specified setbacks.
Lot Setback Parameters: These setting offset the lot perimeter inward for different sides of the lot.
Min Setback Area: This option checks that the lot area within the setbacks is at least this much.

In the Road Network panel click Save or Saveas to save these settings for your own experimentation.

Now Click Process to begin the lot layout. You will notice the ROW’s and EOP’s being generated, followed by the lot lines. Then areas are labeled and setbacks are created. Finally, the lotlines are labeled with distances, bearings and arc data.

Pulldown Menu Location: Area/Layout
Keyboard Command: lotnet_rdn
Prerequisite: centerlines and a site boundary polyline