3R Standards Resurfacing, Restoration, & Rehabilitation Ch. 7 1

3R StandardsResurfacing, Restoration, & Rehabilitation

Ch. 7

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Objectives

• Know what “3R” stands for

• Know basics of 3R standards for freeways

• Know basics of 3R standards for non-freeways

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-Freeway 3R projects (Ch 7)

-Non-Freeway 3R projects (download from lectures)

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Resurfacing

Placement of an additional pavement layer over existing traveled way to provide strength or improve serviceability

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Restoration & Rehabilitation

Work required to return traveled way to a suitable condition for resurfacing while improving highway safety

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3R-Freeways (Oregon DOT I-5 aerial interchange photos)

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Standards same as HDM Ch. 2 for freeways except:

Standards of the Day (Table 7-1, pg 7-11)-widths of lanes, shoulders, median-grades-radii-SSD-Max. Super-Median width

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Needs/deficiencies should be clearly identified

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Pavt Condition & Treatment

• Identify types of deterioration

• Perform a pavement evaluation

• Decide the appropriate corrective action

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Freeway 3R

• Single course overlay (40 mm)• T&L & single course overlay >40mm• Multiple overlays• No extensive replacement of exist. Pavt.• No new additional travel lanes

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Soils

Evaluate when widening pavement

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Utilities

Relocate or remove from clear zone

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Lighting

Rehab, upgrade or remove non-functional lighting

Locate standards outside of clear zone or deflection distance of barrier, or provide breakaway type

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Future MPT

Review potential improvements that could be made to improve future maintenance or construction on the freeway (check w/ maintenance)

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Traffic Data

• Mainlaine (AADT, DDHV, % HV)• Ramps (DDHV)• Crossroads (DHV)• Calc LOS for mainline, ramps, and

intersections• Design year (ETC+10)• Accident analysis (most recent 3 years)

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Non-Conforming Features• LOS• Clear Zone• Intersection Turning Radii• Super Routs and Roffs• Min. Length of vertical curves• Lane drops• Broken back curves• Compound curve ratios• Accel/Decel lane lengths & types • HOV & Transit Accommodations• Weaving Lengths• Design storm for drainage facilities• TCD

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Medians

• Check clear zone

• Emergency crossovers (1:10 or flatter and culverts >300 mm w/ safety grates)

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Curbs

• Usually remove

• If not removed document as a nonconforming feature (historical parkway, drainage, erosion control, structural integrity of bridge)

• Consider traversable versus non-mountable or mountable curb

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Clear zone

• Provide minimum of 9m

• Remove FO

• Identify hazards (cliffs, bodies of water, etc)

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Guide railing

• Consider elimination by regrading• Bring up to current standards• Add new to meet current warrants• Remove trees and FO from deflection area

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TCD

• Update to current MUTCD

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Drainage-Roadside Surface Drainage System

• Site Inspection• Recalculate flow rate/capacities if not

functioning adequately• Roff should not cover more than shoulder and

½ of travel lane to prevent hydroplaning

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Drainage- Cross Drainage Structures

•Site Inspection•Evaluate inadequate structures•Consider replacement of structures that are approaching their anticipated design life

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Drainage- Hazardous Features

•Remove

•Modify

•Shield

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3R: Non-Freeways (http://www.ci.walnut-creek.ca.us/historygifs.html

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3 MAJOR STEPS• Assess current conditions– Accident Data– Site Inspections– Design and Traffic Characteristics

• Determine project scope– Incorporate minor improvements if cost effective

• Document design process– Existing Conditions– Design Criteria (3R)– Design Exceptions– Recommended Design

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3R Standards1. Design Speed2. Pavt./Shoulder Widths

-Retain existing except some min’s are listed or if causing safety/operational problems

3. Pavt/Shoulder Cross Sections– Pavt (1.5-3% accept)– Shoulder (2-8% accept)– Rollover < 8%– Travel lane widths should be constant (vary shoulder

widths if necessary)

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3R Standards4. Horizontal Curvature & Superelevation

-Compare safe operating speed (MUTCD Fig 231-1) to design speed. Depending on difference follow 3R book to determine what to do.-Superelevation transition: Use roff only as minimum. 50-70% on tangent; 30-50% on curve

5. Vertical Curvature/SSD-Don’t consider sag curves unless problem-Crest curves: consider reconstruction if accident problem or all 3 below

criteria are met:i) Crest curve hides a major hazardii) AADT>1500iii) Safe speed > 20mph below design speed

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3R Standards6. Horizontal Clearance to FO

-If no accident, choose minimum of what can be reasonably achieved-Evaluate guiderail for replacement

7. Grades-Retain existing unless operational or safety need

8. Bridges-Evaluate for rehab or replacement-Evaluate width using GDPB

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