Chapter 4

Design Standards
Introduction
This chapter provides specific details about DDOT’s standard settings and symbology
elements, including standard seed files, color table, level names, fonts, etc. This chapter’s
major sections are listed below:

Ɣ Seed Files lists DDOT’s standard seed files for creating new MicroStation V8 files.

Ɣ Standard Settings provides details about the settings contained in the standard
seed files. This includes notes about Working Units, Survey Feet, Coordinate
Readout, Drawing Scale (NEW in V8!), Color Tables and DGN Libraries.

Ɣ Standard Elements provides information about the feature symbology that has
been developed for the V8 standards, including level names, line weights, line styles
and text styles.

Seed Files
When a new dgn file is created, MicroStation makes a copy of the specified template file.
Template files are known as seed files. To ensure design file setup consistency, the following
standard seed files have been created for use on DDOT projects. These seed files should
always be used as a basis for developing any new design files including cell libraries.

Seed File Name Description

DDOTModelSeed2D.dgn Standard 2D model
DDOTModelSeed3D.dgn Standard 3D model

The following seed file has been developed for use when creating bridge or other detail
sheets in MicroStation 2004.

Seed File Name Description

DDOTDetailSeed2D.dgn Self-referenced 2D models at different scales

This seed file consists of multiple V8 Models that are self-referenced at different scales to
facilitate the creation of multiple details at different scales within the same file. (For more
information on working with Multiple Models, refer to the MDSHA V8 CAD Standards
Training Guide in the Documentation directory of the Workspace. As noted previously, in
instances of discrepancy, the DDOT CAD Standards Manual and the DDOT Workspace
shall govern).

DDOT CAD Standards Chapter 4-1 2005

Standard Settings
Working Units
All new V8 design files created for use on DDOT projects must conform to the following
settings, which are incorporated in the seed files (unless otherwise noted):

Global Origin (2D): 0, 0

Global Origin (3D): 0, 0, 0
Master Unit (Label): Survey Feet (’)
Sub Unit (Label): Survey Inch (”)

Resolution: 1000 per Survey Foot

Solids Working Area: >375 Miles

DDOT CAD Standards Chapter 4-2 2005

 Notes on V8 Working Units/Resolution

The MicroStation V8 file format represents a major change in the way that coordinate
data is stored. The 32-bit integer-based design plane has been replaced by a double
precision floating point coordinate system. This has the following practical effects:

1. The V8 design plane is essentially infinite.

2. Positional accuracy, in terms of master units, is essentially unaffected by unit

setup.

3. Unlike Pre-V8 MicroStation, changing the working units does not affect the
size of elements.

In V7, if you draw an element measuring 10 ft, then change the working units from
feet to meters, the element would measure 10 m long. Now with V8, the same change
from feet to meters would result in an element correctly measuring 3.048 m.

While this is an important operational improvement, it also has significant

consequences for the way that DDOT must set up their design files.

International Feet vs. US Survey Feet

By default, a “Foot” in MicroStation actually refers to an International Foot.

However, the state plane coordinate system upon which all DDOT roadway design
projects are based is measured in US Survey Feet.

International Feet: 1 foot = 0.3048000 m

US Survey Feet: 1 foot = 1200/3937 m | 0.3048006 m

The workspace contains a custom units definition file, units.def, which was created by
MDSHA and which defines survey feet and controls the conversion of V7 files to V8.

DDOT CAD Standards Chapter 4-3 2005

 Coordinate Readout
The following coordinate readout settings are delivered in the standard seed files:

Models (2D/3D) Details

Coordinates Format: Master Units Working Units
Coordinates Accuracy: 0.1234 1/64
Angles Format: DD.DDDD DD.DDDD
Angles Mode: Conventional Conventional
Angles Accuracy: 0.1234 0.1234

Drawing Scale
One of the key features of this CAD Standards is the use of a drawing scale which is
displayed along the top of the MicroStation window. (If it does not appear in your window,
select Scale > Display Current Scale from the Main Menu.)

The drawing scale may be changed by selecting the appropriate scale factor from the Main
Menu pulldown. The scale factor is stored with the file.

All scale-dependent drawing elements, i.e. text, cells and linestyles ,have been defined in the
CAD Standards at a unit (1:1) scale. The element is then scaled up or down by the drawing
scale factor when it is selected from a barmenu. This helps maintain consistency of scale-
dependent drawing features, regardless of the scale being used.

DDOT CAD Standards Chapter 4-4 2005

 Programming Note: Before processing any scaling commands, the DDOT Workspace
checks what version of MicroStation is being used (V8.1 or 2004). If it is V8.1, the active
Line Style Scale Factor is used as the default drawing scale. If it is 2004 or later, the Model
Annotation Scale of the active model is used as the default drawing scale. The same Main
Menu > Scale > pull down sets the scale factor for both.

This is a new feature in MicroStation 2004 and has the advantage of being applied at the
Model level (as opposed to the linestyle scale factor which is applied across all models in a
file.)

DDOT CAD Standards Chapter 4-5 2005

 Color Table
The standard color table for all DDOT design projects is ClorDDOT.tbl. The color table is
included on the CD. DDOT personnel can also find it on the sever containing the DDOT
Workspace. This color table defines the RGB values for MicroStation colors 0-255. The
monochromatic (black & white) pen tables have been set up for use with this table such that
all colors plot as black, with the exception of those color values defined below.

232 Gray 10%

233 Gray 20%
234 Gray 30% - shading
Gray 235 Gray 40%
Scale 236 Gray 50% - Linework
237 Gray 60%
238 Gray 70%
239 Gray 80%
240 DDOT Logo Red
241 Blue
242 Orange
243 Yellow
True 244 Blue
Color 246 Green shading
247 Green Lines
252 Red shading
253 Red Lines
254 White to block items out

Refer to the chapter on Plotting for more details.

DGN Library
One of the major new changes to V8 is the use of DGN Library files (DGNLIBS) to
maintain and deliver CAD Standards. The DGNLIB provides these standard items to the user
but locks them from being edited, thus helping to maintain Standards. The standard items can
include the following:

x Levels
x Level Filters
x Text Styles
x Dimension Styles
x Cells

Only level filters and text styles are maintained in the current DDOT’s standard
DGNLIB. All other standard elements are delivered through other methods. Please
refer to the relevant sections below for more information. Once the CAD Standards
mature through testing and use, more of the above items will likely be put into
DGNLIBS.

DDOT CAD Standards Chapter 4-6 2005

Standard Elements
This section describes MicroStation features and the related CAD Standards that must be
followed to maintain consistency across all design files.

Features
A feature corresponds in a very specific manner to a single type of design information
contained within a file type. A feature defines not only a specific piece of information but
also how it is to appear within the design file. A single file type may contain hundreds of
features, each with its own unique set of attributes.

A comprehensive survey of all features in use by Maryland SHA has been made available to
DDOT in-house personnel and the consulting community without modification for use as
needed. It is maintained in the IDSIM database received from SHA, along with all primary
attributes (level, color, weight, and style, which are also known as symbology) and secondary
attributes (including text size, font, etc).

The most important attributes assigned to a feature are level, color, weight and style. Many
other parameters, such as text font, text size and so on may be defined for a particular feature,
but these extra parameters are not necessarily used for identification purposes. By definition,
two elements belong to the same feature whenever they have the same cell name or level,
color, weight and style, even if other parameters may be different.

Barmenus
As a general rule, the barmenus are used to find the standard symbology (level, color, style
and weight) for any item that is contained in the file. If you need an item and can’t find it in
the barmenus or Feature Search tool, contact the appropriate individuals listed in the
Introduction of this manual. A new feature might need to be incorporated into the next
release of the DDOT CAD Standards.

Levels
Levels are named slots for graphical elements in a file whose display can be turned on or off.
This allows users to have lots of information saved in one file, even if all material does not
need to be used or viewed at the same time. MicroStation V8 allows you to define an
unlimited number of named levels.

Level Names

The V8 level naming convention developed at MDSHA is based on the guidelines set
forth by the National CAD Standards with changes as needed to accommodate a civil
transportation workflow. DDOT has adopted the same level naming convention, and
this is shown below:

DDOT CAD Standards Chapter 4-7 2005

 MAJR-MINR-SUBM
Where: MAJR = 4-character Major Group
MINR = 4-character Minor Group
SUBM = 4-character Sub-Minor Group

As shown in the examples below, most of the levels defined in the seed files have no
need to define the sub-minor group. Thus the majority of level names are in the
format MAJR-MINR.

Level Library for Topographic File

Level Libraries

Level names are managed by attaching level libraries. When a barmenu is selected,
the appropriate level library is attached. The library remains attached if you close and
reopen the file. Note that when level libraries are detached, or if the file is opened
outside of the standard DDOT Workspace, used levels will still appear while unused
levels will not.

DDOT CAD Standards Chapter 4-8 2005

 Level libraries have the ability to define level names and descriptions and also by
using the By Level Symbology and Override Symbology for each level. (Note that By
Level symbology has not been adopted in these Standards). All these attributes are
currently maintained for each level library in the IDSIM database. The IDSIM
database can then generate the actual level library files in CSV format, which can be
opened in excel. Therefore, if a level name needs to be modified, all level libraries
using that level can be quickly regenerated. As stated earlier, the MDSHA IDSIM
database has been incorporated in the DDOT Workspace

It is important to mention that levels are not enforced via DGN Libraries for the new
DDOT CAD Standards. Individual level libraries have been created for each file and
can be attached as needed by selecting the appropriate Barmenu from the DDOT
Main Menu. Users also have the option to create new levels as needed and are
encouraged to forward needs and suggestions to the contact person provided in the
Introduction.

Level Filters

Level filters serve two purposes: (1) to limit the number of levels that appear in a
level list and (2) to turn groups of levels on and off when needed. The latter
application is especially useful for controlling level display of attached reference
files.

Standard level filters based on the level

names developed by SHA are delivered as
part of the DDOT Workspace. These
standard filters are maintained in the
levelfilters.dgnlib file. Users may also
create their own filters that are either
temporary or stored in the DGN file
(through the level manager). For more
information, refer to MDSHA’s V8 CAD
Standards Training Guide which is in
the Workspace/Documentation/directory.
(As noted previously, in instances of
discrepancy, the DDOT CAD Standards
Manual and the DDOT Workspace shall
govern).

Line Weights
If plotted line thicknesses are not formally defined, plots tend to have slightly different
appearance depending on the plotter used, the plotting software, driver, pen table, etc. To
avoid this, the DDOT V8 CAD Standards has assigned plotted line thicknesses to
MicroStation weights 0-15 in accordance with industry standard drafting pens.

DDOT CAD Standards Chapter 4-9 2005

 MicroStation Full Size Koh-i-nor Half Size
Weight Thickness (mm) Pen Size Thickness (mm)
wt = 0 0.18 0000 0.09
wt = 1 0.25 000 0.125
wt = 2 0.30 00 0.15
wt = 3 0.35 0 0.175
wt = 4 0.50 1 0.25
wt = 5 0.60 2 0.30
wt = 6 0.70 2.5 0.35
wt = 7 0.80 3 0.40
wt = 8 1.00 3.5 0.50
wt = 9 1.20 4 0.60
wt = 10 1.40 5 0.70
wt = 11 1.70 6 0.85
wt = 12 2.50 8 1.25
wt = 13 3.80 10 1.90
wt = 14 5.00 12 2.50
wt = 15 6.35 14 3.175

Standard pen tables for Iplot and PLT files for MicroStation plotting with the above line
thicknesses defined are delivered in the Workspace. (Refer to the Plotting chapter for more
details). In reality, most standard drafting can and should be accomplished using line weights
0-6, as the weights above 6 are extremely thick.

Thin Lines (wt = 0). Thin lines should be used for existing elements such as
baseline/centerline, existing edge of road, existing sidewalks, existing handicap ramps, etc.
These lines should also be used for depicting background object lines, hidden lines, and most
patterning symbols.

Medium Lines (wt = 1). Medium lines should be used for depicting dimension
leaders/witness lines, dimension lines, dimension text, text for notes/callouts, schedule
boxes/charts, text inside schedules, minor object lines, line terminators (arrowheads, dots,
and slashes) and note leader lines.

Medium Thick Lines (wt = 2, 3). Medium thick lines are the default line weight for drawing
most proposed objects including proposed centerline, edge of road, profiles, proposed inlets
and pipes, etc. Medium thick lines should also be used for section titles.

Thick Lines (wt = 4). Thick lines should be used for minor title underlining, text for titles
and object lines requiring special emphasis.

Extra Thick Lines (wt = 6). Extra thick lines should be used sparingly. Extra thick widths
are appropriate for use as elevation grade lines, building footprints or top of grade lines on
section/foundation details.

DDOT CAD Standards Chapter 4-10 2005

 Line Styles
The size of those line styles that should be scale-dependent has been “unitized”. This
includes such styles as the Woods Line and any style that contains text. When these styles are
used in a drawing, they must be scaled up or down according to the drawing scale (e.g., times
50 for 50-scale).

This appropriate scale factor is applied automatically when these styles are selected from a
barmenu. However, if they are selected through the usual active attribute interface, they may
appear incorrect in the drawing because of an improperly set scale or an on/off toggle that
was pressed accidentally. When this happens, use the commands under the Main Menu to
apply or remove the scale factor setting. (DDOT Main Menu> Scale > Drawing Scale ON,
and so on.)

Custom Line Styles

Custom line styles are user created line styles which can be used to draw linear elements such
as tree lines and drainage pipes and are truly WYSIWYG (“what-you-see-is-what-you-get”).
The custom line styles shown in Appendix E have been delivered with the DDOT
Workspace. These include the symbology for line elements shown in the new DDOT
Engineering and Design Manual.

Cells
One of the key changes to the use of cells in MicroStation V8 is the ability to place cells at
True Scale. E.g., if a cell is drawn 1 foot wideand placed in a metric drawing, it would
measure 0.3048 m. Similarly, V8 will rectify the size of cells drawn in files with different
units of resolution. This is accomplished through the
True Scale setting.

The V8 cells supplied with the DDOT CAD Standards

have been created with units of resolution to match the
standard seed files (meaning that they will always be
true scale). Nevertheless, it is still recommended that
users keep the True Scale checkbox turned on at all
times just in case.

As with the linestyles, most symbol-type cells (i.e. scale-dependent) have been created at a
unit size for easy placement. For these cells, the active scale should be set to match the
drawing scale (i.e. 1”=50’). When selected from one of the barmenus, the correct active scale
will be applied automatically.

DDOT CAD Standards Chapter 4-11 2005

 The standard cells and symbols to be used for the development of roadway plans for DDOT
projects are contained in three cell libraries named DDOT_design.cel, DDOT_survey.cel and
DDOT_traffic.cel. The parameters defined by these cells must be followed on all DDOT
projects.

Numerous cell libraries are supplied with the MDSHA workspace. These libraries are also
included in the DDOT Workspace. Appendix D lists the MDSHA cell libraries supplied with
the Workspace. The cells in these libraries have not been modified in any way. Users should
use the MDSHA supplied cell libraries only if a cell for that feature does not exist in the
DDOT cell library.

Fonts
The CAD Standards have a single resource file (DDOTfonts.rsc) that contains all fonts.

In order to achieve more consistent plan sets, the following standard fonts are recommended
for use:

1 – Working: Proportional font

10/43 – Leroy: Filled font

3 – Engineering: Mono-spaced font

42 – font042: Block font

2 – Fancy: Serifed font

23 - Slanted Slanted font for describing all existing features

Use of these fonts is being encouraged through their implementation as Text Styles.

DDOT CAD Standards Chapter 4-12 2005

 Consultants who require additional fonts for company names or logos may use them as
required. However, it should be recognized that in order for electronically submitted plans to
display properly, the resource file for any added fonts will need to be submitted as well.

Text Styles
MicroStation V8 has introduced a new feature to facilitate the placement of text – Text
Styles. Standard text styles can be created with preset font, text height, text width, etc., for
quick and easy placement. The DDOT Workspace takes advantage of Text Styles in the
following ways:

One of the primary advantages of Text Styles, aside from maintaining consistent appearance
of text, is the ability to propagate the drawing scale to the size of the text. As long as the
Drawing Scale has been properly set from the Main Menu, the size of the text will match. In
MicroStation 2004, this is achieved by enabling the Model Annotation Scale Lock.

x Sample text styles have been placed in the seed files. Note that these are
currently not locked for editing by a DGNLIB file.

x Text Styles are automatically scaled by the active Drawing Scale as follows:

MS V8.1 – changing the drawing scale via the Main barmenu triggers
a macro that scales the text size of all text styles in the file by an
appropriate factor.

MS 2004 – text styles are maintained at unit size (1”=1’) but will be
scaled at the time of placement if the Model Annotation Scale Lock is
enabled.

DDOT CAD Standards Chapter 4-13 2005

 NOTE: In V8.1, if a user changes the drawing scale of a file that already contains text, the
macro will break the association of the text with the text style used to create it. However, this
will not change the appearance of text.

In 2004, the user will be asked if the drawing scale should be applied to existing text… the
recommended response is NO.

Importing Standard Text Styles

If a file was not created based on a standard seed file, it will not contain proper text
style definitions. (This is common for files converted to V8 from an earlier version.)
Similarly, if a file was created in V8.1 and later worked on in 2004, there will likely
be a disconnect with text size (owing to use of the Model Annotation Scale Factor).

To address both of these issues, there is a command on the Main Menu that will
import the standard text styles, scaling them as appropriate. (Main > DDOT Toolbox
> Import DDOT Textstyles) Be careful, however, because this action will delete any
custom text styles you may have created.

Dimension Styles
Dimension Styles are another new MS V8 item. A dimension is a label that shows the linear,
radial or angular measurement of an element. A dimension style is a saved set of
dimensioning settings. Dimension settings can be stored in either a DGN file or a DGN
library. Dimension styles have been created for: Architectural, Structural, Civil, Detail and
Survey. These dimension styles are maintained in the seed files delivered with the CAD
standards rather than in the DGNLIB. As with the Text Styles, missing Dimension Styles
may be imported to a file from the Main Menu (Main > DDOT Toolbox > Import DDOT
Dimension Styles). Once these styles have been refined through use, they may be added to
the DGNLIB file.

DDOT CAD Standards Chapter 4-14 2005

Notes 

DDOT CAD Standards Chapter 4-15 2005