Mississippi Valley Division 

A/E/C CAD Standard 

Supplement 

Mississippi Valley Division 

6 February 2010

Supplement to A/E/C CAD Standard, release 4.0, developed by the CAD/BIM Technology 

Center. 
TABLE OF CONTENTS

i 

1 GENERAL 1-1

Introduction.................................................................................... 1-1

Purpose ............................................................................ 1-1

Platforms .......................................................................... 1-1

Terminology...................................................................... 1-1

2 DRAWING FILE ORGANIZATION .................................................................... 2-1

Design Area................................................................................... 2-1

File Accuracy (units)......................................................... 2-1

Drawing Sheet Assembly .............................................................. 2-1

Use of Design Model and Sheet Model............................ 2-1

Drawing Packages ........................................................... 2-1

Electronic Drawing File Naming Convention................................. 2-1

Design Model Files........................................................... 2-1

Sheet Files........................................................................ 2-2

Drawing Packages ........................................................................ 2-3

Contract Drawing Set ....................................................... 2-3

3 GRAPHIC CONCEPTS...................................................................................... 3-1

Presentation Graphics................................................................... 3-1

Line Widths....................................................................... 3-1

Line Types/Styles ............................................................. 3-1

Line Color ......................................................................... 3-1

Screening ......................................................................... 3-1

Plotting.............................................................................. 3-1

Text Styles and Fonts....................................................... 3-1

Plotting.............................................................................. 3-2

Border Sheets ............................................................................... 3-2

Sheet Sizes ...................................................................... 3-2

Title Block......................................................................... 3-2

Bar Scales ........................................................................ 3-3

View Titles ........................................................................ 3-3

Dimensioning................................................................................. 3-3

General............................................................................. 3-3

4 LEVEL/LAYER ASSIGNMENT.......................................................................... 4-1

Levels/Layers ................................................................................ 4-1

Level/Layer Naming Convention...................................... 4-1

Level/Layer Assignment Tables ....................................... 4-1

5 STANDARD SYMBOLOGY............................................................................... 5-1

Cell Libraries ................................................................................. 5-1

North Arrows .................................................................... 5-1

CAD Symbol..................................................................... 5-1

Safety Symbol .................................................................. 5-1

Value Engineering Symbol............................................... 5-1

6 DRAFTING PRACTICES ................................................................................... 6-1
TABLE OF CONTENTS

ii 

General.......................................................................................... 6-1

Drawing Layout ............................................................................. 6-1

Modular Drawing .............................................................. 6-1

View Orientation ............................................................... 6-1

Required Notation ......................................................................... 6-2

Coordinate Systems......................................................... 6-2

Directional Indicators........................................................ 6-2

Survey Source Data ......................................................... 6-2

Cross Referencing Between Drawings ......................................... 6-2

Section and Detail References......................................... 6-2

Drawing Contents.......................................................................... 6-2

Cover Sheet ..................................................................... 6-2

Location Sheet ................................................................. 6-3

Index Sheet ...................................................................... 6-3

Key Plans ......................................................................... 6-3

Legends............................................................................ 6-3

Survey & Mapping ............................................................ 6-3

Geotechnical .................................................................... 6-3

Reference Drawings......................................................... 6-3
 

Chapter 1 – General 1-1 

1 GENERAL 

Introduction 

This supplement is established to supplement the CAD/BIM Technology Center’s A/E/C 

CAD Standard, and the National CAD Standard. It is intended to be used in conjunction 

with the A/E/C CAD Standards manuals and National CAD Standard. 

Purpose 

The purpose of this supplement is to clarify the proper use of the A/E/C CAD Standard and 

National CAD Standard within the Mississippi Valley Division. Adherence to this 

supplement will provide a consistent platform for developing Computer Aided Drawings, 

and is a prerequisite to achieving good drawing management on Mississippi Valley 

Division projects. 

Platforms 

The target platform for all CAD work is an Intel-based computer running Windows XP (or 

later), and using Bentley Systems’ MicroStation V8 XM Edition (ver. 8.9) (or later). Unless 

specifically exempted, all drawings created by or delivered to a district shall be in a format 

that is fully compatible with the target platform. Compatible files are defined as those able 

to be opened, viewed, modified, re-saved and plotted successfully from their original 

delivered format. 

Terminology 

The terms below are defined as follows: 

Shall – Mandatory action or item on the part of the Contractor 

Should – Preferred, but not required, item or action on the part of the Contractor 

May – Optional action or item on the part of the Contractor 

Will – Pertains to an action by the Government, this term shall not be used to 

refer to an action by the Contractor 

Note: As standard practice, only the term “shall” is to be used on drawings. If in doubt, 

confer with the Specifications Engineer. 

Reference Drawing – A drawing that is part of the contract drawing set that 

reflects existing conditions. 

Reference File – A model file that is referenced into a sheet file. 

Section – A view of an imaginary cut taken through an object to reveal 

the interior construction. 

Detail – A view that further defines an object, usually a blow up of a 

plan or section. 
 

Chapter 2 – Drawing File Organization 2-1 

2 DRAWING FILE ORGANIZATION 

Design Area 

File Accuracy (units) 

Architectural working units shall be as follows: 

Master Units = Feet (‘) 

Sub Units = Inches (“) 

Architectural resolution shall be 304800 per foot. 

Engineering working units shall be as follows: 

Master Units = Survey Feet (ft) 

Sub Units = Survey Inches (in) 

Engineering resolution shall be 304800 per survey foot. 

Drawing Sheet Assembly 

Use of Design Model and Sheet Model 

There shall be one sheet file per drawing. For each sheet file there shall be a maximum of 

one sheet space (required) and one model space. This model space, if used, shall only be 

referenced into its own sheet space; if the model space of the sheet file is referenced any 

where else, then it shall become its own model file. For each model file, there shall be a 

maximum of one model space, with the only exceptions being for cell or design libraries. 

There shall be one title block/border model file per project. 

Drawing Packages 

The work limit tables shall be included in the contract drawing set. The real estate 

drawings showing all applicable interests may be included as reference drawings. 

Electronic Drawing File Naming Convention 

Electronic files shall be named as recommended in Chapter 2 of the A/E/C CAD Standard. 

This naming convention allows for the use of 28 characters, with the first 20 characters 

being optional. The first twenty optional characters, defined as the Project Code in the 

A/E/C CAD Standard, shall be as defined below. The actual number of characters utilized 

in the Project Code field may vary (20 character maximum). However, use of the last eight 

characters of the file name, those immediately preceding the file extension, is mandatory. 

Design Model Files 

The first 20 characters (Project Code) of a design model file name shall consist of a 

ProjectWise (PW) Project code/name and design model file description (optional). The PW 

Project code/name shall be the same for each project drawing file (could be the P2 

number, if unique). The PW Project Code/Name is assigned by the ProjectWise 

Administrator. Use of the underscore symbol “_” to separate the fields is optional. 
 

Chapter 2 – Drawing File Organization 2-2 

EXAMPLE: A model file containing the site plan for Mississippi River would have the 

model file name MR76_SitePlan_C-SP0001.dgn. 

MODEL FILE PROJECT CODE 

(20-character maximum) 

Sheet Files 

The first 20 characters (Project Code) of a sheet file name shall consist of the ProjectWise 

(PW) Project Code/Name. Use of the underscore symbol “_” to separate the fields is 

optional. With the exception of hydrographic data, reference drawings shall follow the 

sheet file naming convention. 

EXAMPLE: A structural sheet file containing concrete outlet plan and sections for a 

Mississippi River plans and specifications drawing set would have the file name MR76_S4010---.dgn. 

SHEET FILE PROJECT CODE 

(20 character maximum) 
 

Chapter 2 – Drawing File Organization 2-3 

Drawing Packages 

Contract Drawing Set 

The drawings within the contract set shall be arranged in the following sequence: 

1. General Drawings 

a. Cover sheet 

b. Vicinity and Location maps 

c. Drawing index sheet (s) 

d. Legend sheet(s) (may be combined with drawing index) 

e. Site plan, general plan, or general arrangements 

2. Scope of work (scope of work may only be included in the drawing set when 

specifications will not be furnished. 

3. Geotechnical Drawings 

a. Boring Log location plan 

b. Boring Logs 

4. Civil Site Drawings 

a. Plan or plan and profile drawings 

b. Profile drawings 

c. Section drawing 

d. Detail drawings 

5. Landscape and Recreation Drawings 

6. Structural Drawings 

7. Architectural Drawings 

8. Mechanical Drawings 

9. Electrical Drawings 

10. Reference drawings (No changes to be made to these drawings) 

a. Hydrographic Data 

b. Existing Condition Drawings 

Drawings within each discipline shall be arranged in sequence of overall perspective or 

fewest details to those drawings containing the most detail, followed by those drawings 

containing supporting information. 
 

Chapter 3 – Graphic Concepts 3-1 

3 GRAPHIC CONCEPTS 

Presentation Graphics 

Unless otherwise specified, presentation graphics shall be as recommended in the A/E/C 

CAD Standard. Line width and color requirements for specific features are listed in the 

A/E/C CAD Standard. 

Line Widths 

Final plotted line widths are determined by the line weights assigned to an element. 

Line Types/Styles 

Only the default, “out-of-the-box“ MicroStation or AutoCAD line styles, or the A/E/C CAD 

Standard supported/furnished line styles shall be used. Custom line styles developed by 

the user shall not be allowed. 

Line Color 

The actual display color associated with a specific MicroStation element color (CO=) is 

defined by the color table attached to the design file. The default MicroStation color table 

is used to standardize the appearance of elements on the computer display. If the user 

has a hard time distinguishing between the assigned colors, the screen color table can be 

modified. However, the line widths used shall be as recommended in the A/E/C CAD 

Standard. 

Screening 

Screened colors (half-tone lines) may be used to depict existing/unchanged features on 

plan, profiles and sections. Grids on profiles & sections may be screened. 

Plotting 

All aerials shall be plotted in grayscale. All sheet files shall be plotted grayscale only. 

Text Styles and Fonts 

The TrueType (TT) font Arial shall be used for text callouts and dimensions. If symbols 

such as “+” or “=” are a part of the text, TT Symbols shall be used. TT Lucida Console 

shall be used for general notes and table/schedule text. TT Arial italicized shall be used 

for labels denoting water, such as river names and the direction of flow. All text shall be in 

upper case unless lower case lettering is needed to define a formula. TT font Black bold 

shall be used for a filled font. 

Text Size 

Dimension, callout, and table/schedule text shall be plotted equivalent to 0.125” (or 3 mm) 

lettering size for all full size A/E/C CAD Standard compliant drawings. Contour line 

elevations, azimuths callouts, boring log text and hydrograph text may be plotted 

equivalent to 0.09375” (or 2.4 mm) lettering size. Sub-titles and Titles shall be plotted 

equivalent to 0.1875” (or 5 mm) and 0.25” (or 6 mm) lettering sizes, respectively. The text 
 

Chapter 3 – Graphic Concepts 3-2 

height and text width shall be assigned equal number values. Line spacing shall be equal 

to one half of the text height. 

Drawing Callouts 

The “Place Note” command shall be used for all drawing callouts in MicroStation. 

“Generate Leader” shall be toggled on and “Association” is recommended to be toggled 

on when using this command. Callouts shall be left justified, and whenever possible, they 

shall be aligned. Callout text shall be placed so that it appears horizontal on the sheet file. 

Callout leaders shall never cross text, dimension lines, or each other. Placing callout 

leaders through dimension extension lines shall be avoided whenever possible; however, 

if this type of placement is necessary, the extension line shall be broken where the leader 

line passes through it. This shall be accomplished without dropping the dimension. 

When placing callouts, long lines shall be avoided so each callout remains within the 

modular area of the detail. If the leader to the multi-line callout is on the right side, the 

lines of text subsequent to the first line of text should be no longer than the first line of 

text whenever possible. 

General Drawing Notes 

Notes shall be placed in the upper right corner of the drawing whenever possible. Notes 

shall be contained within a single text node with upper left justification. Standard notes 

designating the units of measure shall appear on each metric drawing. 

Plotting 

Plotting is keyed from the line weight of the line work within the drawing. To achieve the 

proper line width and grayscale color (screening) on the plotted copy, the appropriate line 

weight and pen tables shall be used. 

Border Sheets 

Sheet Sizes 

ANSI D size borders shall be used for all drawings. Drawings shall be plotted half-size 

when included in reports. ANSI A size borders may also be used for sketches/drawings to 

be included in reports. 

Title Block 

Sheet identification block. The sheet identification block (Figure 3-6) shall only contain 

the sheet identification as defined in the A/E/C CAD Standard. 

Figure 3-6. Sheet identification block 
 

Chapter 3 – Graphic Concepts 3-3 

Bar Scales 

Sheet files containing scaled views shall contain the appropriate graph bar scale(s). 

When imperial units are used, a graph bar scale shall be placed for each scale used on the 

drawing. For metric drawings, only one graph bar scale representing the scale of the 

primary view on the drawing shall be used. Graph bar scales from the general cell library 

shall be used. 

Figure 3-7. Sample graph bar scale 

View Titles 

View titles shall be placed using the symbols available on in the general cell library. View 

titles shall be centered under the view. 

Dimensioning 

General 

The automatic dimensioning features of MicroStation shall be used for all dimensioning. 

Association shall be toggled on. If the extension line is broken to accommodate the 

placement of a callout leader, the association shall be dropped. 

Filled arrowheads shall be used as dimension terminators. 
 

Chapter 4 – Level/Layer Assignments 4-1 

4 LEVEL/LAYER ASSIGNMENT 

Levels/Layers 

Level/Layer Naming Convention 

All level or layer naming for projects within the Mississippi Valley Division shall conform 

to the AIA Format described in the A/E/C CAD Standard. 

Level/Layer Assignment Tables 

For all new project starts, the level/layer assignment tables found in the A/E/C CAD 

Standard shall be used. 
 

Chapter 5 – Standard Symbology 5-1 

5 STANDARD SYMBOLOGY 

Cell Libraries 

General use cell libraries shall be used for all non-specific discipline symbology (e.g. 

north arrows, scale bars, section cuts, etc.). Project specific cell libraries shall be placed 

in the appropriate discipline folder of the project directory. 

North Arrows 

The north arrow used shall be either the cell NORIND or NORTH1. The location of the 

north arrow shall be consistent (or as consistent as possible) within the drawing set. 

Figure 4-1. NORIND cell Figure 4-2. NORTH1 cell 

CAD Symbol 

There shall not be any CAD symbols shown on any sheets. 

Safety Symbol 

There shall not be any safety symbols shown on any sheets. 

Value Engineering Symbol 

There shall not be any Value Engineering symbols shown on any sheets. 
Chapter 6 – Drafting Practices 6-1 

6 DRAFTING PRACTICES 

General 

In general, all features shall be drawn to scale. Prefabricated items for which exact 

dimensions may vary depending on the manufacturer shall be drawn proportional. 

Connecting feature/component lines shall connect (i.e., do not “eye-ball” feature lines; use 

the snap and precision placement features which are a part of the CAD software). When 

break or match lines are used, feature lines shall be terminated at the break or match line. 

Match lines connecting two sheets shall match exactly. 

For 3D files, 2D elements (such as text, real estate line, etc) shall be placed at elevation 

zero. 

Drawing Layout 

Modular Drawing 

Modular drawing is an organizational technique that uses a grid to divide each drawing 

sheet into a system of drawing spaces called modules. All drawing areas shall be placed 

in a module or group of modules. Parts of one drawing area shall not enter into a module 

occupied by an adjacent drawing area. Leaving space between modules helps to clearly 

information pertaining to each module and enhances the overall appearance of the 

drawing. 

View Orientation 

Views shall be orientated on the sheet so that elevation and features are aligned when 

ever possible. When detailing, details shall appear on the sheet based on their orientation 

on the feature. For instance, a detail of the top of a wall shall be orientated above a detail 

of the bottom of the wall. If a detail is taken from a large-scale plan or elevation, the 

orientation shall remain the same as the view from which the cut was taken. If this not 

possible, a note stating the orientation was changed will be added (e.g., VIEW ROTATED 

90 DEGREES). When two or more plans of the same structure or the plans of two or more 

different structures are put on the same drawing, the orientation of all must conform to 

one another and to their relative positions on the ground. 

Civil maps (e.g., site plans, general plans, etc.) will be oriented so north is toward the top 

of sheet, or toward the right of the sheet if top orientation is impractical. 

Flood control and navigation drawings (plans, elevations, and longitudinal sections of 

channels, levees, locks, dams, and similar structures). Cross-sections will be shown as if 

the observer were looking downstream. Stationing shall read up station and be from left 

to right, and shall take precedence over a north orientation. 

Roadways and other structures. General plans, elevations, and longitudinal sections of 

roadways and other structures will be so oriented that north will be toward the top of 

sheet, or toward the right of the sheet if top orientation is impracticable. Stationing will be 

from west to east or south to north. Cross-sections will be shown as if the observer were 

looking up station. Stationing shall read up station (perpendicular to control line). 
Chapter 6 – Drafting Practices 6-2 

Required Notation 

Coordinate Systems 

The specified coordinate system/datum (usually State Plane) shall be denoted on maps 

(civil plans) whenever possible. The grid system used shall be described in the general 

notes. 

Directional Indicators 

The direction of water flow of all waterways will be indicated by the standard district flow 

symbol, at the upper and lower limits of sheet, pointing in the direction toward which the 

water moves. The true meridian will be shown on all maps or charts of land or water areas 

and, when useful, the magnetic declination (dated) should also be given. 

Survey Source Data 

All maps shall list the source of data used to generate the map to include scale, and type 

of source (e.g., USGS QUADRANGLE 1:24,000, AERIAL MAPPING at 1 in = 50 ft, 3rd LEVEL 

FIELD SURVEYS, SURVEY BOOK NUMBER, OR DATE OF SURVEY). This information 

shall also be included in the General Notes of a drawings set. 

Cross Referencing Between Drawings 

All Drawings shall be cross-referenced using the Sheet Reference Number located in the 

sheet identification block of the border. 

Section and Detail References 

Sections shall be denoted alpha characters. Details should use numbers for identification. 

A combination of alpha and numeric characters may be used, provided that the first 

character of a section is an alpha character and the first character of a detail is numeric. 

All alpha characters shall be capitalized. When referencing sections/details from another 

sheet, use characters unique to the drawing set (don’t reuse letters/numbers). 

Drawing Contents 

The drawings are the instructions to the builder. They must be accurate, easily 

interpreted, and leave nothing to guess work. Drawings shall be prepared so that they 

convey the complete meaning intended with a minimum number of details. Drawings shall 

be prepared so that each drawing contains only one major category type per drawing (e.g., 

plan & profile, sections, details, miscellaneous metals). 

Cover Sheet 

The cover sheet, or first drawing in the set, shall include the approval signature block. The 

approval signature block is not required on the cover sheet for report and real estate 

drawings. If required by the owning district, the AE signature block/stamp shall be placed 

on the cover sheet where there is space. The date on the cover sheet shall be the month 

and year of drawing completion; for the solicitation drawing package, this would be the 
Chapter 6 – Drafting Practices 6-3 

month and year advertisement. The solicitation number is only required on the cover 

sheet for the plans and specifications drawing set. The plans and specification drawing 

set cover sheet shall be plotted on Mylar for signature, and then scanned to create a PDF 

file. 

Location Sheet 

The location sheet is the second drawing in the set and shall include the location map and 

vicinity map. The purpose of the vicinity map is to show major access routes to the 

project site. The location sheet shall be in engineering working units. 

Index Sheet 

The index sheet is the third drawing in the set. This sheet shall contain the index of all 

drawings in the set and list the reference drawings. If space permits, the sheet may 

contain the general legend and symbols. If there is not adequate space, additional 

drawings may be added for the indexing and/or the general legend and symbols. 

Key Plans 

If Key Plans are used, the following describes the specifics. Key Plans shall be shown on 

each plan view sheet. The Key Plan shall consist of a shape representing each plan view 

sheet. The footprint of the proposed project shall be shown. Additional project 

information (either existing or proposed) shall not be shown. There shall be a north 

arrow. The Key Plan shall be shown with north to the top of the sheet. The shape 

representing the plan view sheet that the Key Plan is on shall be hatched. The location on 

the sheet shall be consistent within the drawing set. It is recommended to be located in 

the upper right or the lower right of the border. 

Legends 

Legends shall be shown on the legend sheet. They shall not be repeated on each 

plan/profile sheet. 

Survey & Mapping 

Contours shall not cross contour text or buildings/structures. 

Geotechnical 

There shall be a plan view showing the locations of the boring logs. This may be a 

separate Geotechnical plan view or in combination with the Civil plan view. 

Reference Drawings 

Reference drawings are drawings that are included at the end of the drawing set that 

portray existing or historic conditions. These drawings are used for reference only, and 

shall not be changed.