Design Exceptions 101Design Exceptions 101

Ed Fischer, State Traffic-Roadway EngineerMike Morrow, FHWA Field Operations EngineerKent R. Belleque, Senior Interchange Engineer

Items to Cover TodayItems to Cover Today

• Design Exception Background• Key Items in Design Exceptions

– Timelines– Evaluation Criteria– Justification– Helpful Tools

• Planning Level Design Exceptions• Case Studies (Helpful Hints)• Expectations from Ed and Mike• Q & A

Chief Engineer’s RoleChief Engineer’s Role

• Authority for Design Standards• Outlined in Title 23 CFR 625• Oregon Highway Design Manual (HDM)

Approval of Exceptions to Standards• Delegated to State Roadway Engineer

• Contact with FHWA on Process

Expectations from ODOTExpectations from ODOT

• Provide Enough Information that Convinces the Reviewer to Approve not Achieving the Standard

Can we get to Yes?

When Should the Process Begin?When Should the Process Begin?

• Start Discussion ASAP with ODOT• Allow Sufficient Time for Review• May also Require Approval by FHWA• Insufficient Data will Require More Time

What Should be Included?What Should be Included?

• General Discussion on the Design Exception• Evaluation of the Exception• Justification• Review and Approval (Tech Center and FHWA

Level)

Areas of Special NoteAreas of Special Note

• Vertical Clearance and Motor Carrier Contact

Areas of Special NoteAreas of Special Note

• 3R- Roadside Design- Documented @ Region

Areas of Special NoteAreas of Special Note

• Form has been updated– Top 10% SPIS– Interchange Spacing

Other Available ToolsOther Available Tools

• Highway Safety Analysis Tools – http://www.oregon.gov/ODOT/HWY/TRAFFIC-ROAD

WAY/highway_safety.shtml– Crash Data– SPIS/SIP– Crash Reduction Factors

Flexibility in Design-FHWAFlexibility in Design-FHWA

• Design Exceptions– Consideration of Safety

and Operations– Consideration of Crash

History and Roadway Character

– Cost to Attain Full Standard and Impact on Environmental Features

– Degree of Reduction• Impact on other

Standards• Mitigation

Flexibility in Design-AASHTOFlexibility in Design-AASHTO

• Similar to FHWA Guidance– Proper Justification– Crash analysis, Rationale

for Exception

• Stresses Importance of Documentation

Flexibility in Design- 1R and SFFlexibility in Design- 1R and SF

• TRB Special Report 214- 3R Practices

• 1R and Single Function Impact on Design Exceptions?????

Design Exceptions on a National Design Exceptions on a National Level Level • Dealing with Same

Issues as ODOT– Why are Design

Exceptions Done?• 42%- Reduces Liability• 40%- Design

Exception Documentation

• Number of Exceptions Varies

NCHRP Synthesis 316NCHRP Synthesis 316

• Type of Exceptions Similar

Planning Design ExceptionsPlanning Design Exceptions

• Planning Studies Need to Follow Design Standards– Design Elements Need to Meet Standard or Get an

Exception– If Elements are Unknown, don't Show Specific Dimensions

• Timing of Planning Design Exceptions– Construction in 5 years-Process the Exception Before

Putting in Planning Document– Construction in 5-10 years-Submit Draft Design Exception

and Obtain Written Indication of Approval/Denial

Non-Design Exceptions IssuesNon-Design Exceptions Issues

• PLA01-Review Process for Design Concepts on ORS 366.215 Routes– Vehicle Carrying Capacity

and Lane Reductions

Tech Services- To Do List Tech Services- To Do List

• Design Speed• Horizontal and Vertical Angle Points• 3R- Criteria A & B• Others??

Real Life Examples: Case 1Real Life Examples: Case 1

Specifically it is requested that the following design features not be further evaluated: horizontal alignment, vertical alignment, grades, lane width, shoulder width, bridge width and the correction of deficient bridge rails and missing ADA sidewalk features, roadway cross slopes, cut/fill/ditch slopes, access, and clear zone.

Case 2: Reasons for Not Attaining Case 2: Reasons for Not Attaining StandardStandard

The Request: Case 3The Request: Case 3

Case 3 (Continued)Case 3 (Continued)

The Request: Case 4The Request: Case 4

Items to RememberItems to Remember

• Look at Crash Data• Number and Type of Exceptions• Cost by Itself is not a Good Justification• Look for Ways to Mitigate

– Striping– Signing– Illumination

Items to RememberItems to Remember

• Identify Design Exceptions ASAP• Work with Design Exception Review Team in

Salem– Christopher Henson Rural Roadway Engineer– Rich Crossler-Laird Urban Roadway Engineer– Kent Belleque Interchange Engineer– Dan MacDonald Roadside Safety Engineer– Dave Polly Standards Engineer– And Others

• Allow Sufficient Time for Processing

Web Page LinksWeb Page Links

• Design Exceptions– http://egov.oregon.gov/ODOT/HWY/ENGSERVICES/de

sign_exceptions.shtml– Request Form Instructions– Required Signatures

• Technical Bulletins– http://egov.oregon.gov/ODOT/HWY/ENGSERVICES/

tech_bulletin.shtml

Comments from ODOT and FHWAComments from ODOT and FHWA

• Ed Fischer and Mike Morrow

• Q and A