MnDOT Computer Aided Design and Drafting (CADD) links
CADD Resources and Data Standards *This page has the download file for the cell library (including fonts, line styles, seed files and level libraries): MNDOT-CDStds-MSTN.zip
Intersection Design – Our current practice for the majority of opposing left turns uses a WB-62 design vehicle opposing a Passenger car (P) design vehicle, and making sure they can safely pass each other in the intersection when making their respective left turns (in both directions), without using split phase, lead/lag or locking left turns. In some cases, we may design opposing WB-62’s if the demand for both left turn approaches is warranted. For example, if a UPS terminal is on one side and a FedEx terminal on the other, along with heavy industrial zoning which requires heavy truck use, we would design for opposing WB-62 left turns because the frequency of opposing trucks would be greater.
At Grade Intersections - Check the Intersection Sight Distance for Case F – Left Turns from the Major Road (See Technical Memorandum No. 18-06-TS-04). Flashing Yellow Arrows may be installed with this project, or in the future.
Turning template paths should provide 2.5 foot clearance to the face of curbs - [Reference: MnDOT Road Design Manual (RDM) 5-2.04.02]. For Roundabouts - Turning template paths should provide a minimum of 1 foot and preferably 2 feet to the face of curbs. Use guidance from NCHRP Report 672, section 6.4.3 when laying out vehicle paths.
Turn paths for the double left turns should be laid out using a WB-62 in the outside lane and a 14 foot strip alongside on the inside of the turn for a passenger vehicle - [Reference: MnDOT Road Design Manual (RDM) 5-3.01.06].
Throat widths for double left turns should desirably be 36 feet, with a minimum of 30 feet - (Reference: RDM 5-3.01.06).
On freeway projects, exit ramps – Has the 10 second decision sight distance been checked? Reference RDM 2-5.08.04: Height of eye = 3.5 feet, height of object = 0 feet which is the beginning of the striped gore area.
Design Guidelines for Locating Wet Ponds with Permanent Water Depths along Freeways and High Speed Highway (FDG, Section 13E.2.4)
Diamond interchanges, cross street over mainline, at the exit ramp/cross street intersection – Intersection Sight Distances:
Through/Stop Control – Compute the left turn from stop and right turn from stop distances. Check these distances against the profile of the cross street.
Signal Control - Compute the right turn from stop distance, for right turn on red. Check this distance against the profile of the cross street.
Compute Stopping Sight Distance for barriers between vehicles and pedestrians.
Use Standard Plate 7109 at the first introduction of a raised median nose when going from an undivided roadway to a divided roadway. Use Standard Plate 7113 at the beginning of raised medians and raised islands to ease snow plow blades on divided roadways.
Provide 6 foot bike cutouts along roadway for bikes to access the trail adjacent to the roundabout. Refer to NCHRP Report 672, section 6.8.2.2, for guidance.
The Designer shall check for obstructions to the sight lines to signal heads. Coordinate with Metro Traffic Signal personnel. Submit computations, as attachments, to the submittal letter.
Graphically show Intersection Sight Distances on profiles, or profile details.
