• ♦Manual Notice 2022-2
• ►Preface
• ►1. Design General
  • ►1. Overview
    • ♦Application of Design Guidelines
    • ♦Roadway Design Manual Format
    • ♦External Reference Documents
  • ►2. Design Exceptions, Design Waivers, Design Variances, and Texas Highway Freight Network (THFN) Design Deviations
    • ♦Overview
    • ♦Design Exceptions
    • ♦Design Waivers
    • ♦Design Variances
    • ♦Texas Highway Freight Network (THFN) Design Deviations
  • ►3. Schematic Development
    • ♦Overview
    • ♦Schematic Development Process
    • ♦Schematic Layout
    • ♦Schematic Approval
  • ♦4. Access to the Interstate System
  • ♦5. Preliminary Design
  • ♦6. Maintenance Considerations in Design
• ►2. Basic Design Criteria
  • ►1. Overview
    • ♦Introduction
  • ►2. Functional Classifications
    • ♦Overview
  • ►3. Traffic Characteristics
    • ♦Overview
    • ♦Traffic Volume
    • ♦Speed
    • ♦Terrain
    • ♦Safety
    • ♦Additional Considerations
  • ►4. Sight Distance
    • ♦Overview
    • ♦Stopping Sight Distance
    • ♦Decision Sight Distance
    • ♦Passing Sight Distance
    • ♦Intersection Sight Distance
    • ♦Sight Distance at Under-Crossings
  • ►5. Horizontal Alignment
    • ♦Overview
    • ♦General Considerations for Horizontal Alignment
    • ♦Curve Radius
    • ►Superelevation Rate
    • ♦Sight Distance on Horizontal Curves
  • ►6. Vertical Alignment
    • ♦Overview
    • ♦Grades
    • ♦Vertical Curves
    • ♦Grade Change without Vertical Curves
    • ♦Vertical Alignment at Railroad Crossings
    • ♦Vertical Alignment at Intersections
    • ♦Vertical Clearance
    • ♦Combination of Vertical and Horizontal Alignment
  • ►7. Cross-Sectional Elements
    • ♦Overview
    • ♦Pavement Cross Slope
    • ♦Median Design
    • ♦Lane Widths
    • ♦Shoulder Widths
    • ♦Pavement Taper Lengths
    • ♦Curb and Curb with Gutters
    • ♦Roadside Design
    • ♦Slopes and Ditches
    • ♦Lateral Offset to Obstructions
    • ♦Clear Zone
  • ►8. Drainage Facility Placement
    • ♦Overview
    • ♦Introduction
    • ♦Design Treatment of Cross Drainage Culvert Ends
    • ♦Parallel Drainage Culverts
    • ♦Side Ditches
  • ♦9. Roadways Intersecting Department Projects
• ►3. New Location and Reconstruction (4R) Design Criteria
  • ►1. Overview
    • ♦Introduction
  • ►2. Urban Streets
    • ♦Overview
    • ♦Level of Service
    • ♦Basic Design Features
    • ♦Medians
    • ♦Median Openings
    • ♦Clear Zones
    • ♦Borders
    • ♦Berms
    • ♦Grade Separations and Interchanges
    • ♦Right-of-Way Width
    • ♦Intersections
    • ♦Speed Change Lanes
    • ♦Drainage Horizontal Offsets
    • ►Bus Facilities
    • ♦Bus Streets
  • ►3. Suburban Roadways
    • ♦Overview
    • ♦Basic Design Features
    • ♦Access Control
    • ♦Medians
    • ♦Median Openings
    • ♦Clear Zones
    • ♦Borders
    • ♦Grade Separations and Interchanges
    • ♦Right-of-Way Width
    • ♦Intersections
    • ♦Speed Change Lanes
    • ♦Parking
  • ►4. Two-Lane Rural Highways
    • ♦Overview
    • ♦Basic Design Features
    • ♦Access Control
    • ♦Transitions to Four-Lane Divided Highways
    • ♦Passing Sight Distances
    • ♦Speed Change Lanes
    • ♦Grade Separations and Interchanges
    • ♦Intersections
  • ►5. Multi-Lane Rural Highways
    • ♦Overview
    • ♦Basic Design Features
    • ♦Level of Service
    • ♦Basic Design Features
    • ♦Access Control
    • ♦Medians
    • ♦Turn Lanes
    • ♦Travel Lanes and Shoulders
    • ♦Intersections
    • ♦Transitions to Four-Lane Divided Highways
    • ♦Converting Existing Two-Lane Roadways to Four-Lane Divided Facilities
    • ♦Grade Separations and Interchanges
  • ►6. Freeways
    • ♦Overview
    • ♦Basic Design Criteria
    • ♦Access Control
    • ♦General
    • ♦Mainlane Access
    • ♦Frontage Road Access
    • ♦Control of Access Methods
    • ♦Control of Access by Design
    • ♦Mainlanes
    • ♦Design Speed
    • ♦Level of Service
    • ♦Lane Width and Number
    • ♦Shoulders
    • ♦Medians
    • ♦Outer Separation
    • ♦Crossing Facilities
    • ♦Vertical and Clear Zones at Structures
    • ♦Frontage Roads
    • ♦Function and Uses
    • ♦Planning
    • ♦Design Speed on Frontage Roads
    • ♦Capacity and Level of Service
    • ♦Frontage Road Design Criteria
    • ♦Conversion of Frontage Roads from Two-Way to One-Way Operation
    • ♦Grade Separations and Interchanges
    • ♦Three-Leg Interchanges
    • ♦Four-Leg Interchanges
    • ♦Diamond Interchanges
    • ♦Cloverleaf Interchanges
    • ♦Directional Interchanges.
    • ♦Interchange Spacing
    • ♦Auxiliary Lanes
    • ♦Ramps and Direct Connectors
    • ♦General Information
    • ♦Design Speed
    • ♦Ramp Geometrics
    • ♦Gores
    • ♦Cross Section and Cross Slopes
    • ♦Sight Distance
    • ♦Ramp Terminal Design
    • ♦Exit Ramps to Frontage Roads
    • ♦Ramp Spacing
    • ♦Metered Ramps
    • ♦Collector-Distributor Roads
    • ♦Frontage Road Turnarounds and Intersection Approaches
  • ►7. Freeway Corridor Enhancements
    • ♦Overview
    • ♦Freeways with High Occupancy Vehicle Treatments
    • ♦Light Rail Transit
    • ♦Peak Hour Lanes
    • ♦Tolled Express Lanes
  • ►8. Texas Highway Freight Network (THFN)
    • ♦Overview
    • ♦Vertical Clearance at Structures
    • ♦Signs, Overhead Sign Bridges (OSB’s), Signals
    • ♦Other Overhead Utilities
• ►4. Non-Freeway Rehabilitation (3R) Design Criteria
  • ►1. Purpose
    • ♦Overview
    • ♦Design Guidelines
  • ►2. Design Characteristics
    • ♦Pavement Design
    • ♦Geometric Design
    • ♦Design Values
    • ♦Alignment
    • ♦Design Speed
    • ♦Side and Backslopes
    • ♦Lane Widths
  • ►3. Designing for Safety
    • ♦Overview
    • ♦Safety Design
    • ♦Basic Safety Improvements
    • ♦Other Safety Improvements
  • ►4. Frontage Roads
    • ♦Overview
  • ►5. Bridges, Including Bridge-Classification Culverts
    • ♦Overview
  • ►6. Super 2 Highways
    • ♦Overview
    • ♦Basic Design Criteria
  • ►7. 3R Project Documentation
    • ♦Project-Specific Design Information
    • ♦Plan Set Requirements
• ►5. Non-Freeway Resurfacing or Restoration Projects (2R)
  • ►1. Criteria
    • ♦Overview
    • ♦Definition
    • ♦Upgrading
    • ♦Crash Analysis
• ►6. Special Facilities
  • ►1. Off-System Bridge Replacement and Rehabilitation Projects
    • ♦Overview
    • ♦Design Values
  • ►2. Historically Significant Bridge Projects
    • ♦Reference for Procedures
  • ►3. Texas Parks and Wildlife Department (Park Road (PR) and Park and Wildlife Road (PW)) Projects
    • ♦Working Agreements
  • ►4. Bicycle Facilities
    • ♦6.4.1 General
    • ♦6.4.2 Planning and Context
    • ♦6.4.3 Elements of Design
    • ♦6.4.4 Bikeway Types
    • ♦6.4.5 Intersections and Crossings
    • ♦6.4.6 Maintenance, Operations, and Work Zone
    • ♦6.4.7. References
• ►7. Miscellaneous Design Elements
  • ►1. Longitudinal Barriers and Roadside Safety Hardware Criteria
    • ♦Overview
    • ♦Concrete Barriers (Median and Roadside)
    • ♦Guardrail
    • ♦Attenuators (Crash Cushions)
    • ♦Roadside Safety Hardware Crash Criteria
  • ►2. Fencing
    • ♦Overview
    • ♦Right-of-way
    • ♦Control of Access Fencing on Freeways
  • ►3. Pedestrian Facilities
    • ♦7.3.1 General
    • ♦7.3.2 Elements of Design
    • ♦7.3.3 Linear Pedestrian Facilities
    • ♦7.3.4 Curb Ramp Design
    • ♦7.3.5 Driveway Design Considerations
    • ♦7.3.6 Intersections and Crossings
    • ♦7.3.7 Overcrossings and Underpasses
    • ♦7.3.8 Work Zone and Temporary Traffic Control Pedestrian Accommodations
    • ♦7.3.9 Lighting
    • ♦7.3.10 On-Street Parking
    • ♦7.3.11 Transit Access
    • ♦7.3.12 Railings Adjacent to Steep Slopes
    • ♦7.3.13 Additional Considerations
    • ♦7.3.14 Micromobility Vehicles
  • ►4. Parking
    • ♦Overview
    • ♦Fringe Parking Lots
    • ♦Parking Along Highways and Arterial Streets
  • ►5. Rumble Strips
    • ♦Overview
    • ♦Considerations for Centerline and Shoulder Rumble Strip Placement
    • ♦Bicyclists Considerations
  • ►6. Emergency Crossovers
    • ♦Overview
    • ♦Location
    • ♦Construction
  • ►7. Minimum Designs for Truck and Bus Turns
    • ♦Overview
    • ♦Application
    • ♦Channelization
    • ♦Alternatives to Simple Curvature
    • ♦Urban Intersections
    • ♦Rural Intersections
    • ♦Median U-Turn Movements
• ►8. Mobility Corridor (5 R) Design Criteria
  • ►1. Overview
    • ♦Introduction
  • ►2. Roadway Design Criteria
    • ♦Overview
    • ♦Lane Width and Number
    • ♦Shoulders
    • ♦Pavement Cross Slope
    • ♦Vertical Clearances at Structures
    • ♦Stopping Sight Distance
    • ♦Grades
    • ♦Horizontal Alignment
    • ♦Superelevation
    • ♦Superelevation Transition
    • ♦Vertical Curves
  • ►3. Roadside Design Criteria
    • ♦Clear Zone
    • ♦Slopes
    • ♦Medians
  • ►4. Ramps and Direct Connectors
    • ♦Overview
    • ♦Design Speed
    • ♦Lane and Shoulder Widths
    • ♦Acceleration and Deceleration Lengths
    • ♦Distance Between Successive Ramps
    • ♦Grades and Profiles
    • ♦Cross Section and Cross Slopes
• ►A. Longitudinal Barriers
  • ►1. Overview
    • ♦Introduction
  • ►2. Barrier Need
    • ♦Overview
    • ♦Types of Barrier
    • ♦Applications
    • ♦Working Width
  • ►3. Structural Considerations of Guard Fence
    • ♦Overview
    • ♦Post Spacing, Embedment, and Lateral Support
    • ♦Rail Element
    • ♦Blockouts
  • ►4. Placement of Guard Fence
    • ♦Overview
    • ♦Lateral Placement at Shoulder Edge or Curb Face
    • ♦Lateral Placement Away from the Shoulder Edge
    • ♦Deflection Considerations
  • ►5. End Treatment of Guard Fence
    • ♦Overview
  • ►6. Determining Length of Need of Barrier
    • ♦Overview
    • ♦Variables
    • ♦Design Equations
    • ♦Using Design Equations to Determine Length of Guard Fence
  • ►7. Example Problems
    • ♦Example Problem 1
    • ♦Example Problem 2
    • ♦Example Problem 3
  • ►8. Median Barrier
    • ♦Overview
    • ♦Application
    • ♦Placement
    • ♦Additional Cable Median Barrier Guidance
  • ►9. Emergency Crossovers
    • ♦Overview
    • ♦Location
    • ♦Construction
• ►B. Treatment of Pavement Drop-offs in Work Zones
  • ►1. Overview
    • ♦Scope
    • ♦Types of Treatment
    • ♦Factors Affecting Treatment Choice
    • ♦Edge Condition
    • ♦Guidelines for Treatment
• ▼C. Driveway Design Guidelines
  • ♦1. Overview
  • ►2. Introduction
    • ♦General Guidelines
    • ♦Definitions
  • ►3. Driveway Design Principles
    • ♦General Guidelines
    • ♦Geometrics for Two-Way Driveways
    • ♦Divided Driveways
  • ►4. Profiles
    • ♦Driveway Grades
    • ♦Profiles on Curb and Gutter Sections
    • ♦Profiles with Drainage Ditch
  • ►5. Driveway Angle
    • ♦Two-Way Driveways
    • ♦One-Way Driveways
  • ►6. Bicycle and Pedestrian Considerations
    • ♦General Guidelines
  • ♦7. Visibility
  • ♦8. References
• ►D. Right-Turn Slip Lane Design Guidelines
  • ♦1. Introduction
  • ►2. New Construction
    • ♦Urban Design
    • ♦Suburban Design
    • ♦Rural Design
  • ►3. Retrofitting Treatments
    • ♦Providing Proper Refuge for Pedestrians
    • ♦Stopping and Yielding to Crossing Pedestrians
    • ♦Crosswalk Location
    • ♦Reducing Speeds in the Channelized Roadway
    • ♦Enhancing Visibility of Crossing Pedestrians
    • ♦Reducing Head Turning to Spot Oncoming Traffic
    • ♦Slip Lane Removal
  • ♦4. References
• ►E. Alternative Intersections and Interchanges
  • ►1. Overview
    • ♦Introduction: Alternative Intersections and Interchanges
    • ♦Pedestrian Considerations for Alternative Intersections
  • ►2. Roundabouts
    • ♦Overview
    • ♦Planning
    • ♦Geometric Design
    • ♦Entry Width
    • ♦Circulatory Roadway Width
    • ♦Entry Curve
    • ♦Exit Curve
    • ♦Roundabout Speeds
    • ♦Vertical Geometry
    • ♦Cross-Slope
    • ♦Splitter Islands
    • ♦Pedestrian Considerations
    • ♦Bicyclist Considerations
    • ♦Access Management
  • ►3. Diverging Diamond Interchange (DDI)
    • ♦Overview
    • ♦Design Considerations
    • ♦Sight Distance
    • ♦Horizontal Alignment Alternatives
    • ♦Auxiliary Lanes
    • ♦Pedestrian and Bicyclist Considerations
    • ♦Access Management
  • ►4. Median U-Turn Intersection (MUT)
    • ♦Overview
    • ♦Design Considerations
    • ♦Location Considerations
    • ♦Pedestrian and Bicyclist Considerations
    • ♦Access Management
  • ►5. Restricted Crossing U-Turn Intersection (RCUT)
    • ♦Overview
    • ♦Design Considerations
    • ♦Intersection Angle
    • ♦Pedestrian and Bicyclist Considerations
    • ♦Access Management
  • ►6. Displaced Left Turn Intersection (DLT)
    • ♦Overview
    • ♦Design Considerations
    • ♦Sight Distance
    • ♦Pedestrian and Bicyclist Considerations
    • ♦Access Management
  • ♦7. References

Section 8: References

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1. A Policy on the Geometric Design of Highways and Streets, American Association of Highway and Transportation Officials.
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2. Transportation and Land Development, Institute of Transportation Engineers, 2002.
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3. TxDOT Access Management Manual.
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4. Proposed Accessibility Guidelines for Pedestrian Facilities in the Public Right of Way, July 2011.
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5. R. J. Jaeger, Guidelines for the Investigation and Remediation of Potentially Hazardous Bicycle and Pedestrian Locations, Traffic Engineering and Safety Management Branch, North Carolina Department of Transportation, August 2003.
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6. Charles V. Zegeer, Cara Seiderman, Peter Lagerway, Mike Cynecki, Michael Ronkin and Robert Schneider, “Pedestrian Facilities Users Guide – Providing Safety and Mobility,” Publication No. FHWA No. FHWA-RD-01-102, Federal Highway Administration, US Department of Transportation, March 2002.
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7. NCHRP Report 659 Guide for the Geometric Design of Driveways, Transportation Research Board of the National Academies, 2010.