Design Manual

Chapter 1 — General Information

1A	Introduction
	1A-1...................About This Manual
1B	General
	1B-1..................Glossary and Abbreviations
	1B-2...................Contact Information
	1B-4...................Densities for Use in Estimating Quantities
	1B-5...................Pipe Thickness Table
	1B-6...................Project Cost Estimates
	1B-7...................Managing Changes in Project Concepts
1C	Standards and Design Criteria
	1C-1...................Selecting Design Criteria
	1C-7...................Public Interest Findings
	1C-8...................Documenting Design Decisions
1D	Plan Development
	1D-1...................Project Flow Chart
	1D-3...................Preliminary Survey Procedure
	1D-4...................Pavement Determination Process
	1D-7...................Interchange Review
	1D-8...................Access Review Submittal
	1D-9...................Field Examination Checklist (New and Reconstructed Highways)
	1D-10.................Field Examination Checklist (3R and 4R Projects)
	1D-14.................Lighting Warrants Request
	1D-15.................Design Public Meeting Displays
	1D-20.................Reviewing Railroad Crossings at Side Roads
	1D-21.................Flood Debris Removal Plans
1E	Plan Preparation
	1E-1....................Certification of Plans
	1E-3....................Plan Revisions
	1E-4....................Road Design Details
	1E-5....................Standard Road Plans
	1E-6....................Designer Information for Standard Road Plans
	1E-7....................Designer Information for Road Design Details
	1E-8....................Plan Submittals for County Review
	1E-9....................Standard Notes
1F	Plan Sheets
	1F-1....................Plan Sheets – General Information
	1F-2....................A Sheets
	1F-2a..................Title Sheet
	1F-2b..................Location Map Sheets
	1F-2c..................Plan Revision Sheets
	1F-3....................B Sheets
	1F-3a..................Typical Cross Sections
	1F-4....................C Sheets
	1F-4a..................Project Description Tabulation
	1F-4.5..................CS Sheets
	1F-5....................D Sheets
	1F-5a..................Plan and Profile Legend and Symbol Information Sheet
	1F-5b..................Plan and Profile Sheets
	1F-6.....................E Sheets
	1F-7.....................F Sheets
	1F-8.....................G Sheets
	1F-9.....................H Sheets and HE Sheets
	1F-10...................J Sheets
	1F-11...................K Sheets
	1F-12...................L Sheets
	1F-12b...........Intersection Layout Sheets
	1F-13...................M Sheets
	1F-13.5..............MIT Sheets
	1F-14...................N Sheets
	1F-15...................P Sheets
	1F-16...................Q Sheets
	1F-16.1................QR Sheets
	1F-17...................R Sheets
	1F-18...................S Sheets
	1F-19...................SPS Sheets
	1F-20...................T Sheets
	1F-21...................U Sheets
	1F-22...................V Sheets
	1F-23...................W, X, and Y Sheets
	1F-23a............Cross Section Spacing and Sheet Dimensions
	1F-24...................Z Sheets
1G	Bid Item Information
	1G-1...................Bid Item Determination and Quantity Estimation
	1G-4...................Bidding Mobilizations for Watering
	1G-5...................Bidding Mobilizations for Erosion Control
	1G-6...................Salvaged Materials
	1G-7...................Monitoring with Incident Response
	1G-8...................Items Left in Place between Projects
	1G-10.................Bidding Alternate Items
	1G-11.................Railroad Insurance
	1G-14.................Pavement Incentive/Disincentive Bid Items
1H	Final Plan Preparations
	1H-1...................Plan Turn-In
	1H-2...................Changes After Plan Turn-In
	1H-3...................Communication with Contractors and Field Staff

Chapter 2 — Alignments

2A	Horizontal Alignment
	2A...................Horizontal Alignment
2B	Superelevation
	2B...................Superelevation
2C	Vertical Alignment
	2C...................Vertical Alignment

Chapter 3 — Cross Sections

3A	Roadways
	3A-1...................Typical Roadway Sections
3C	Shoulders and Curbs
	3C-2...................Curbs
	3C-3...................Shoulder Cross Slope
	3C-3.5................Shoulder Design Changes
	3C-4...................Shoulder Design
	3C-5...................Shoulder and Centerline Rumble Strips
	3C-6...................Safety Edge
	3C-10...................Earth Shoulder Construction and Earth Shoulder Finishing
3D	Subgrade and Subbase
	3D-1...................Subgrade Slopes
	3D-2...................Grading on Multi-Year Four Lane Divided Roadway Projects
	3D-3...................Pavement Drainage and Strength Layers
3E	Medians
	3E-1....................Medians
	3E-2....................Median Crossings
	3E-3....................Temporary Median Crossovers
3F	Foreslopes
	3F-2....................Foreslopes at Drainage Structures
	3F-3....................Transverse Slope Adjustment at Entrances and Safety Ramps
3G	Ditches
	3G-1...................Roadway Ditches
	3G-2...................Intercepting Ditches
3J	Berms and Benches
	3J-1.....................Berms and Benches
3K	Access Points
	3K-2...................Access Design

Chapter 4 — Drainage

4A	Urban Drainage Design
	4A-1...................Introduction to Stormwater Drainage System Design
	4A-2...................Stormwater Drainage System Information Sources, Documentation, and Permitting
	4A-3...................Effects of Roadway Geometrics On Pavement Drainage
	4A-4...................Concept Plan
	4A-5....................Using the Rational Method to Determine Peak Flow
	4A-6...................Calculating Spread and Checking Intake Location
	4A-7...................Open-throat Curb Intakes
	4A-8...................Barrier Grate Intakes
	4A-10.................Storm Sewer Design
	4A-11.................Cost Estimates and City Agreements
	4A-12.................Removing or Abandoning Storm or Sanitary Sewer
	4A-13.................Removing Intakes or Manholes
4B	Rural Drainage Design
	4B-1...................Determining Entrance and Safety Ramp Pipe Culvert Lengths
	4B-2...................Livestock Passes
	4B-3...................Removing or Abandoning Culverts
4C	Miscellaneous
	4C-1...................Subdrains
	4C-2...................Bridge End Drains for Capturing Stormwater Runoff

Chapter 5 — Earthwork

5A	General
	5A-1...................Earthwork Flowchart
	5A-2...................Earthwork Essentials
	5A-3...................Earthwork Deliverables for Plan Turn-in
5B	Excavation and Borrow
	5B-1...................Rock Excavation
	5B-2...................Culvert Excavation and Backfill
	5B-3...................Bidding Contractor Furnished Borrow
5C	Earthwork Quantities
	5C-11...................Roadway Earthwork Bid Item Descriptions

Chapter 6 — Geometric Design

6A	Geometric Design of Intersections
	6A-1...................Horizontal Intersection Design: Rural Two-Lane
	6A-2...................Intersection Design Vehicle
	6A-3...................Modern Roundabouts-General Guidance
	6A-3a.................Roundabout Feasibility Initial Screening Tool
	6A-7...................Rumble Strips at Intersections
	6A-8...................Intersection Alignment (Rural Primary Highways)
	6A-9...................Edge Profiles
	6A-10...................Intersection Edge of Traveled Way Design (Edge Returns)
	6A-11...................Stop Sign Islands
6B	Geometric Design of Interchanges
	6B-1...................Cross Sections of One and Two Lane Ramps and Loops
	6B-2...................County Roads through Interchanges
	6B-3...................County Roads over Primary Highways
	6B-6...................Accesses and Safety Dikes at Ramp/Loop Terminals
6C	Geometric Design of Lanes
	6C-1...................Adding, Dropping, or Redirecting Through Lanes
	6C-2...................Super-2 Highways
	6C-5...................Four-Lane Expressway Turn Lanes
	6C-6...................Continuous Two-Way Left-Turn Lanes (TWLTLs)
	6C-8...................Parking on Urban Highways
6D	Sight Distance
	6D-1...................Sight Distance

Chapter 7 — Pavement

7A	Portland Cement Concrete
	7A-2...............Jointing Guidelines
	7A-3...............Jointing Rural Intersections
	7A-4...............Jointing Urban Intersections
	7A-5...............Jointing Cul-de-Sacs
	7A-6...............Jointing Ramp and Loop Terminals
7C	Granular Surfaces
	7C-1...............Granular Surfacing
7D	Other
	7D-1...............Determination of Reinforced Bridge Approach Section Dimension
	7D-4...............Treatment of Old Roadbeds
	7D-8...............Pavement Widening on Resurfacing Projects for Non-NHS Highways
	7D-10.............Tabulating Adjustment of Manholes, Intakes, Fire Hydrants, and Other Fixtures

Chapter 8 — Roadside Safety

8A	Introduction
	8A-1...................Introduction to Roadside Safety
	8A-2...................Clear Zones
	8A-3...................Treatment Options for Objects within the Clear Zone
	8A-4...................Warrants for Specific Objects
	8A-5...................Roadside Safety Hardware Assessment
	8A-6...................Zone of Intrusion
8B	Treatments
	8B-2...................Culvert Opening Safety Treatments
	8B-5...................Choosing a Barrier
	8B-6....................Locating a Barrier
	8B-10.................Tabulating Guardrail
8C	Barrier Design
	8C-1...................Concrete Barrier Rail
	8C-2...................Steel Beam Guardrail
	8C-3...................High Tension Cable Guardrail
	8C-5...................Crash Cushions
	8C-6...................Treatment of Existing Guardrail Installations

Chapter 9 — Traffic Control

9A	Principles
	9A-1...................Fundamental Principles of Traffic Control in Work Zones
	9A-2...................Traffic Control Zones
	9A-3...................Tapers
	9A-4...................Regulatory Speed Limit Changes
	9A-5...................Traffic Control Plans
9B	Traffic Control Devices
	9B-1...................Basic Requirements of Traffic Control Devices
	9B-2...................Signs
	9B-3...................Channelizing Devices
	9B-4...................Raised Pavement Markers and Delineators
	9B-5...................Warning Lights
	9B-6...................Floodlights
	9B-7...................Arrow Displays
	9B-8...................Changeable Message Signs
	9B-9...................Temporary Barrier Rail
	9B-10.................Road Closures
	9B-11.................Speed Feedback Trailer Signs
9C	Work Zone Applications
	9C-1...................Introduction to Work Zone Activities
	9C-2...................Work Located Off the Traveled Way
	9C-3...................Work on Two-Lane Roadways
	9C-4...................Work on Multi-Lane Roadways
	9C-5...................Control of Traffic through Incident Areas
	9C-6...................On-Site Detours and Temporary Connections
	9C-7...................Haul Road Crossings
9D	Pavement Markings
	9D-1...................Pavement Markings
9E	Traffic Control
	9E-1...................Traffic Critical Projects Program
9F	Traffic Control in Work Zones
	9F-1...................Introduction to Traffic Mobility and Safety Mitigations
	9F-2...................Mobility and Safety Mitigations by Work Type
	9F-3...................Proposal Mitigations
	9F-4...................Design Mitigations
	9F-6...................Traffic Operations
	9F-7...................Intelligent Work Zone Applications
	9F-8...................Traffic Incident Management Plan
	9F-9...................Public Information

Chapter 10 — Roadside Development and Erosion Control

10A	Topsoil
	10A-1.................Topsoil Replacement
10B	Seeding, Fertilizing, and Mulching
	10B-1.................Seeding, Fertilizing, and Mulching
10C	Erosion Control
	10C-1.................Temporary Sediment Control Devices
	10C-2.................Storm Water Detention
	10C-3.................Vegetated Buffers
	10C-4.................Temporary Sediment Control Devices for Intakes and Manholes
	10C-5.................Temporary Sediment Control in Urban Areas
	10C-6.................Creating the Erosion Control Features DSN File
10D	Storm Water Discharge Permits for Maintenance Projects
	10D-1.................Storm Water Discharge Permits
	10D-2.................Storm Water Discharge Permits for Maintenance Projects
10E	Fencing
	10E-1..................Fencing

Chapter 11 — Other Design Topics

11D	Miscellaneous
	11D-1.................Casing Pipe
	11D-2.................Noise Wall Design Process
	11D-3.................Iowa DNR Paddling Route Determination and Plan Development

Chapter 12 — Pedestrian and Bicycle Facilities

12A	Pedestrian Facilities
	12A-1.................General Sidewalk Requirements
	12A-2.................Accessible Sidewalk Requirements
	12A-3.................Protruding Objects
	12A-4.................Pedestrian Facilities During Construction
	12A-5.................Pedestrian Safety Measures and Crossings
12B	Bicycle Facilities
	12B-1.................Selecting Bicycle Facilities
	12B-2.................Shared Use Path Design
	12B-3.................On-Street Bicycle Facilities
	12B-10...............Pedestrian Path Guidelines: Safety Rail
12C	Detailed Design Criteria
	12C-1.................Check for ADA Compliance

Chapter 20 — Project Automation Information - V8i

20A	Starting a New Project - General
	20A-1................Start New MicroStation Project
	20A-2................Survey Request
20B	Folders and Files
	20B-41................Project Directory Folder Structure
	20B-45................File Naming CCRRRPPPGGG Notation
	20B-51................Folder and Files, Photo and Survey
	20B-71................Electronic Files Supplied by the Design Bureau
	20B-72................Engineering Content to Review in Digital Deliverables
	20B-73................Methods for Reviewing Digital Deliverables Content
	20B-75................Office of Location and Environment File Exchange
	20B-81................Project Directory Letting Folder Structure
20D	GEOPAK Setup and General Information
	20D-101.............OpenRoads Files and Naming Conventions
	20D-102.............OpenRoads Element Naming Conventions
20J	Project Bid Items & Quantities (PSS)
	20J-61................Calculation Files
	20J-62................Earthwork Calculation Program
	20J-71................Project Locator
	20J-81................Accessing the Project Scheduling System
	20J-82................Bid Item Information
	20J-86................Alternate Bid Item Sheet Exporting

Chapter 21 — Automation Tool Instructions - V8i

21C	MicroStation
	21C-71............... Geographic Coordinate Systems in MicroStation
21F	DOT ProjectWise System
	21F-1................NonDOT User Access to Iowa DOT ProjectWise System
	21F-10..............ProjectWise Basics
	21F-21..............Exporting and Importing Documents from ProjectWise
	21F-22..............ProjectWise Hyperlinks
	21F-23..............ProjectWise Email Attachments
	21F-24..............ProjectWise Replacing Documents
	21F-25..............Reference Scanning CADD Files in ProjectWise
21M	Miscellaneous Topics
	21M-1.................FTP Site Access
	21M-12...............Create File and Folder Listing
	21M-39..............Work Schedule Instructions
	21M-41..............Long Term Project E-mail Storage
	21M-42..............How to Capture the Full Path to a File
	21M-51..............Superelevation Transition Evaluation Tool

Chapter 22 — MicroStation ORD Connect

MicroStation ORD instructional videos

Chapter 40 — Design Survey Specifications

40B	Surface Topography Data Collection
	40B-1.................Feature Codes – Full Descriptions
	40B-2.................Feature Codes - Titles Only
	40B-3.................Feature Codes - Categories
	40B-4.................Feature Codes - Modifications
	40B-5.................Full and Partial DTM Surveys
	40B-7.................Bridge Data Collection
	40B-8.................Culvert Data Collection
	40B-9.................Storm Sewer Intakes and Manhole Data Collection
	40B-10...............Feature Codes for Roadway Survey
	40B-11...............Feature Codes for Entrance and Intersection Survey
	40B-12...............Feature Codes for Curb & Gutter Survey
40D	MicroStation and GEOPAK Survey Mapping Process
	40D-1.................Folder Structure and File Naming
	40D-2................Survey Preferences
	40D-3.................Loading Datasets
	40D-4.................Editing Survey Data
	40D-5.................Checking for Crossing Chains
	40D-6.................Creating Horizontal Alignments
	40D-7.................Processing Datasets in Models and Zones
	40D-8.................Build DTM from Elements
	40D-9.................Build DTM from Survey Data
	40D-10...............Editing the DTM
	40D-11...............Drawing Contours
	40D-12...............Using Design and Computation (D&C) Manager
	40D-13...............Drawing Horizontal Alignments
	40D-14...............Station and Offset Reports
	40D-15...............Completing the G Sheet
	40D-16...............GEOPAK Survey TOPO Model Links
	40D-17...............How to Use the Survey Information

Chapter 120 — Specifications

120A	Specifications Documents
	120A-1...............Specifications Overview
	120A-2...............Developmental Specifications
	120A-3...............Special Provisions
	120A-4...............Writing Specifications

Chapter 200 — Geotechnical Design

200A	Overview of Geotechnical Design
	200A-1...............Introduction
	200A-2...............Project Coordination
	200A-3...............Geotechnical Consultant Services and Review
200B	S Events
	200B-1...............The S1 Event
	200B-2...............The S2 Event
	200B-3...............The S3 Event
	200B-4...............The S4 Event
200C	Surface Investigation Methods
	200C-1...............Subsurface Investigation Methods
200D	Laboratory Testing
	200D-1...............Laboratory Testing
200E	Engineering Properties of Soil and Rock
	200E-1...............Engineering Properties of Soil and Rock
200F	Analysis, Design, and Treatment
	200F-1...............Slope Stability
	200F-2...............Embankments
	200F-3...............Mechanically Stabilized Earth (MSE) Wall Evaluations
	200F-4...............Driven Pile Design
	200F-5...............Drilled Shaft Design
	200F-6...............Intermediate Foundation Improvements (IFIs)
	200F-7...............Prefabricated Vertical Wick Drains (PVDs)
	200F-8...............Rock Cut Slopes
	200F-9...............Geosynthetic Design
	200F-10.............Landslide Analysis and Mitigation
	200F-11.............Soil Cut Slopes
200G	Construction Involvement
	200G-1...............Construction Involvement
200H	Emergency Relief Projects
	200H-1...............Emergency Relief Projects
200I	Appendix A – Consultant Geotechnical Work Requirements
	200I-1...............Appendix A - Consultant Geotechnical (Soils Design) Work Requirements

Design Manual Video Index

Design

Design Manual

1A

Introduction

1B

General

1C

Standards and Design Criteria

1D

Plan Development

1E

Plan Preparation

1F

Plan Sheets

1G

Bid Item Information

1H

Final Plan Preparations

2A

Horizontal Alignment

2B

Superelevation

2C

Vertical Alignment

3A

Roadways

3C

Shoulders and Curbs

3D

Subgrade and Subbase

3E

Medians

3F

Foreslopes

3G

Ditches

3J

Berms and Benches

3K

Access Points

4A

Urban Drainage Design

4B

Rural Drainage Design

4C

Miscellaneous

5A

General

5B

Excavation and Borrow

5C

Earthwork Quantities

6A

Geometric Design of Intersections

6B

Geometric Design of Interchanges

6C

Geometric Design of Lanes

6D

Sight Distance

7A

Portland Cement Concrete

7C

Granular Surfaces

7D

Other

8A

Introduction

8B

Treatments

8C

Barrier Design

9A

Principles

9B

Traffic Control Devices

9C

Work Zone Applications

9D

Pavement Markings