Roadway Standard Cadd "File Type" Naming Convention /(See Note 1)

(See Design File Generator Utility in NCDOT Workspaces

All 2D MicroStation Graphics Files Should Have a ".dgn"  Extension

DRN		Drainage File (See Note 2)
DSN		Proposed Roadway Design File
EOP		Edge of Existing Pavement File
LAY		Plan Sheet Layout File
PAT		Pattern Line File
PHM		Public Hearing Maps
PFL		Proposed Profile Design File
PSH		Plan Sheet Files
ROW		Proposed ROW File
SHP
SPD		Shear Point Diagram
SS		Slope Stake File
STR_REC		Structure Recommendations
SUM		Summary Sheets File
SVY_REQ		Survey Requests
TSH		Title Sheet File
TYP		Typical Sheets File
XPL		Cross-Section Sheet Layout File
XSC		Cross-Section File

---

Note 1:
This list refers only to the "file type" portion of the entire cadd file name. The standard for the entire file name is as follows:
(TIP Number)_(Unit Abbreviation)_(File Type)_(Description).dgn

Also, a distinction should be made between electronic file names and hard copy production plan sheet numbers. Electronic file names are logical file names that may or may not reflect the hard copy production plan sheet numbers. An example would be the ".xpl" electronic file name. This electronic file name may contain numerous hard copy production plan sheet numbers such as X-1, X-2, X-3, etc; in this particular case possibly as MicroStation models.

Note 2:
As a rule, the roadway designer should reference the ".drn" file created by the Hydraulics Unit from the "Drainage" folder and use it as the proposed drainage file. If necessary, however, the roadway designer may copy the ".drn" file from the "Drainage" folder and modify the unit code from "hyd" to "rdy" to add or modify ditches. No drainage structures (inlets, catch basins, pipes, culverts, etc.) should be added or modified in any way by the roadway designer. These type changes should be made by the hydraulics designer versus the roadway designer.

---

MicroStation 3D Graphics Files Not Requiring a ".dgn"Extension

DTM			Digital Terranin Model / Approved File Type
DTL			Digital Terrain Model / Old File Type from Location Surveys
DTP			Digital Terrain Model / Old File Type from Photogrammetry

MicroStation Binary (Non-Graphics) Files That Should Never Have a ".dgn" Extension

TIN			Binary File Containing Triangle Data / Approved File Type
TNL			Binary File Containing Triangle Data / Old File Type from L&S
TNP			Binary File Containing Triangle Data / Old File Type from Photogrammetry