i n t e g r a t i n g c s s practitioner module 5 1 module 5: css and livability in project...

I n t e g r a t I n g C S S

Practitioner Module 5

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Module 5: CSS and Livability in Project Development



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By the end of this module you will be able to: Recognize how CSS applies to project development Recognize the importance of design team

communications for effective integration of CSS



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Lesson 1: What is Project Development?

Lesson 2: Basics for Integrating CSS into Design

Lesson 3: Flexible Engineering Design Explained

Lesson 4: Challenges or Barriers to CSS Integration in Design Lesson

Lesson 5: Commitments Tracking into Construction



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CSS in Project Development Focus on:

– Delivery of the constructed project – the preferred alternative, final approvals, funding and construction

Measure:– The details that will decide how the

project is to be bid and be built

Integrate CSS to:– Make detailed design decisions,

manage risks, and build the project in response to context

CSS Integration Guide, Chapter 2.4



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What is Project Development?

A significant focus and investment in delivery of constructed projects– Identifying and refining the preferred alternative (and its impacts)– Achieving the final project approvals and funding– Design the project and prepare it for construction



Practitioner Module 5Project Development and

Evaluation Framework

Establishes criteria for measuring effectiveness of alternatives

Develops comprehensive but not redundant criteria

Defines data needs

Focuses study effort

Sets stage for alternative formulation


Practitioner Module 5Alternatives Development

Universe of alternatives includes full range of stakeholder values

Formulates each alternative to best advantage

Assures each alternative Is minimally feasible

Ensures alternatives are competitive



Two Dimensional Plans or Drawings are Often Insufficient



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Basics for Integrating CSS into Design

Keys to success in project development:– Deliver stakeholder and design process in

parallel with the regulatory/NEPA– Consider every project unique

Integrating CSS in Design Decisions




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Basics for Integrating CSS and Livability into Design

Interdisciplinary stakeholder input is critical

Weighing trade-offs among seemingly competing values




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Flexible Engineering Design Explained

Design Speed

Design Level of

Service

Design Vehicle

Creativity in Highway

Design

Creativity in Surface

Transportation

A Guide to Achieving Flexibility in Highway Design




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Design Speed – Design speed is a selected speed used to determine the various geometric design features of the roadway.

Level of Service - The term level of service refers to the quality of traffic flow during a designated design period (typically expressed as a design hourly volume)

Design Vehicle: Design vehicle characteristics that influence the footprint, right-of-way and operations include the length and width, wheelbase, and turning characteristics




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Creativity in Surface Transportation Reframing how a problem is described can help achieve

creative solutions For example, demand or access management solutions

may be more feasible to implement than capacity expansions




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Creativity in Highway Engineering

Simply means not routinely applying the same

solutions or approach everywhere

Can be fostered by re-directing designers toward

thinking of performance-based solutions

Puts the emphasis on excellent project team

communications




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‘Level of service’ is the accepted framework for characterizing traffic operational quality.

Levels range from A to F, with Level E representing operation at capacity.



http://www.levalleyphoto.com/gallery/



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Higher LOS means– Larger “footprint” (greater adverse impacts and costs)– Improved safety (sometimes)

Lower LOS– Lesser R/W and other physical impacts– More frequent “congestion”– Less reliability – Less flexibility (future uncertainty)


LOS guidance is based on driver expectation…




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CSS, Safety, and Design Exceptions CSS does not mean compromising safety Many routine and uncontroversial design decisions

involve some safety tradeoffs These tradeoffs are based on our experience with

substantive safety No studies have established that design exceptions

increase with CSS




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The Two Dimensions of Safety Nominal safety – refers to adherence to design practices,

standards, warrants, etc.

Substantive safety – refers to actual (or expected)

performance

DOT

Design

Manual

When highway design professionals talk about “safety,” they are often talking about adherence to standards, which is nominal safety

= Safe Design Practices

???




Substantive Safety is a Continuum

g Which model more closely describes what stakeholders are thinking?



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Many “nominally safe” locations experience crash problems…

Full Cloverleaf Interchanges: Loops create weaving (crossroad,

mainline) Severe speed changes are required for

exiting and entering traffic Research indicates poor safety history for

moderate to high volumes of traffic Cloverleafs are still included in the

AASHTO design policy





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Some “nominally unsafe” locations experience no crashes…





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Stakeholders should understand these points about safety:

Substantive safety varies widely by project context Combinations of design features, dimensions and

elements influence substantive safety Substantive safety involves both crash frequency

and severity





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Design Exceptions -- An Introduction

• When an applicable design value or ‘standard’ can not be attained, it may be necessary to obtain a design exception

• Design exceptions may apply on any highway or road, under a range of contexts

• Design exceptions are nothing new• Design exceptions must be fully documented





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The 13 geometric design elements that affect the safety and operational quality of a highway (according to FHWA)

Design speed Lane width Shoulder width Normal cross slope Horizontal curvature Superelevation Tangent grade

Vertical curvature Vertical clearance Stopping sight distance Bridge width Horizontal clearance Structural capacity

NOTE: In CSS, think of design exceptions as “non-standard” design not

“sub-standard” design! CSS Integration Guide, Chapter 9.3



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Design Exceptions and Risk Management Formal design exceptions review assures appropriate effort and

thought to design problem and solution

Documentation is critical for design exceptions to address risk and

provide for risk management

Design

Exceptions

Report*

Project xx




Tort Liability as it Relates to the Green Book

Adherence to the Green Book does not automatically establish reasonable care.

Deviation from the Green Book does not automatically establish negligence.

Designers are expected to make complex decisions and to document them.

Sometimes a unique, creative design solution is needed and expected.

Good design involves applying flexibility and judgment to solve the problem.



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Challenges or Barriers to CSS Integration in Design

Design manuals and policies Project management procedures Separating technical work, assigning it to different

entities Continuity of project staff Managing stakeholders and integrating project

development/design work




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Challenges or Barriers to CSS Integration in Design

Internal/organizational CSS Integration Issues Existing organizational structures may lead to “second

guessing” Changing the way transportation agencies

assign/manage design work offers opportunities to improve CSS integration

Integration of CSS at the project level requires team empowerment and flatter decision-making structures


i n t e g r a t i n g c s s practitioner module 5 1 module 5: css and livability in project...

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