APPLYING PERFORMANCE-BASED PRACTICAL 

DESIGN METHODS TO COMPLETE STREETS:

A Primer on Employing Performance-Based Practical Design and Transportation 

Systems Management and Operations to Enhance the Design of Complete Streets

PRACTICAL DESIGN FOR OPERATIONS
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Cover Photo Source: Kittelson & Associates, Inc.
Dowling, R., Jenior, P., Nevers, B. (Kittelson & Associates, Inc.); 

Neudorff, L. (CH2M)

Kittelson & Associates Inc.

300 M Street SE, Suite 810

Washington, DC 20001

Technical Report

Informational Report

Sept 2014 to July 2016

FHWA

This Primer explains how the application of performance-based practical design (PBPD) principles combined with 

transportation system management and operations strategies (Operations strategies) can promote the consideration 

and application of Complete Street design principles to a wider range of contexts.

Complete Streets often involve a reduction or re-purposing of the number of motor vehicle travel lanes on the street. 

This frees up space for safety and operational improvements benefiting more users of the street: auto drivers, truck 

drivers, transit passengers, bicyclists, and pedestrians. PBPD, combined with operations strategies, enables the 

designer to consider applying Complete Street design concepts to a wider range of contexts. The result is a street 

system that cost-effectively meets the needs of the diverse users of the streets and the objectives of the agency.

FHWA-HOP-16-059

Applying Performance Based Practical Design Methods to 

Complete Streets - A Primer on Employing Performance-Based 

Practical Design and Transportation Systems Management and 

Operations to Enhance the Design of Complete Streets

September 2016

Jim Hunt (jim.hunt@dot.gov) served as the Technical Manager for FHWA

Performance-Based Practical Design,

Complete Streets, Urban Streets

48

FormDOTF 1700.7(8-72) Reproduction of completed page authorized

Conversion Factors

7

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Overview and Purpose of the Primer 11

Chapter 1 Complete Streets: Description and

 Design Considerations 13

Design and Operational Components of Complete Streets 14

The Design Objective: Making it Fit, Balancing Needs 15

Further Reading on Complete Streets Design 15

Chapter 2 Performance-Based Practical Design 17

Performance-Based Practical Design 17

Relationship Between Performance-Based Practical Design and

Context Sensitive Solutions 20

Design Criteria and Design Exceptions 20

Transportation System Management and Operations 21

Chapter 3 Employing Performance-Based Practical Design and 

 Transportation System Management and Operations 23

Setting The Design Objectives and Performance Measures 23

Identifying Candidate Design Concepts 23

Role of Transportation System Management and Operations in Complete Streets 28

Further Reading on Transportation System Management and Operations Strategies 29

Chapter 4 Analyzing the Tradeoffs 31

Lane Widths-Operational Effects on Motor Vehicles 31

Lane Widths-Safety 32

Effects of Lane Reconfigurations on Capacity 33

Effects of Complete Streets on Reliability 33

Combined Effects of Complete Streets on Safety and Mobility 33

Capacity Effects of Complete Streets Employing Road Diets 34

Safety Effects of Complete Streets Employing Road Diets 34

Further Reading on Safety and Mobility Effects 34

Table of Contents
U.S. Department of Transportation | Federal Highway Administration

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Chapter 5 Case Studies 35

Case Study #1 – Edgewater Drive, Orlando, Florida 36

Project Setting 36

Performance-Based Practical Design 36

Before and After Analysis 36

Case Study #2 – Cordova Street, Pasadena, California 38

Project Setting 38

Performance-Based Practical Design 38

Before and After Analysis 38

Case Study #3 – Ingersoll Avenue, Des Moines, Iowa 40

Project Setting 40

Performance-Based Practical Design 40

Before and After Analysis 40

Case Study #4 – Employing Transportation Systems Management and

Operations to Expand Application of Complete Streets 41

Traffic Operations Analysis 41

Identification of Operations Problems, Development of Transportation Systems

Management and Operations Solutions 41

Chapter 6 Summary and Conclusions 43

References 45

Table of Contents (continued)
9

Operations in Performance-Based Practical Design: A Primer on Complete Streets

List of Figures

Figure 1. Diagram. Performance-Based Practical Design + Transportation

 Systems Management and Operations -> Better Complete Streets. 11

Figure 2. Photo. Complete Streets Example. 12

Figure 3. Photo. Example Complete Street Result. 12

Figure 4. Photo. Prototype Complete Street. 13

Figure 5. Diagram. Framework for Performance-Based Planning and Programming. 18

Figure 6. Diagram. Concepts and Activities Associated with Performance-Based Practical Design. 19

Figure 7. Flowchart. An Objectives-Driven, Performance-Based Approach. 22

Figure 8. Chart. Levels of Separation of Bicycle Treatment Options. 25

Figure 9. Photos. Additional Bicycle and Pedestrian Design Treatment Examples. 26

Figure 10. Diagrams. Application of Performance-Based Practical Design to Generate

 One of Many Potential Complete Street Design Concepts. 27

Figure 11. Photos. Edgewater Drive, Orlando – Before and After Road Diet. 37

Figure 12. Diagrams. Edgewater Drive Road Diet Configuration. 37

Figure 13. Diagrams. Cordova Street, Pasadena, California – Before and After Road Diet. 39

Figure 14. Diagrams. Cordova Street Road Diet Configuration. 39

Figure 15. Diagrams. Ingersoll Avenue, Des Moines, Iowa – Before and After Road Diet. 40

List of Tables

Table 1. Example. Performance-Based Practical Design Performance Analysis Matrix. 24

Table 2. Example. Applications of Transportation Systems Management and

 Operations Strategies to Support Performance-Based Practical

 Design in Complete Streets. 28

Table 3. Lane Width Adjustment Factors for Urban Signalized Intersections. 32

Table 4. Effects of Narrow Lanes on High Speed Roadway Free-Flow

 Speed and Capacity. 32
U.S. Department of Transportation | Federal Highway Administration

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List of Acronyms and Symbols

AADT Average Annual Daily Traffic

AASHTO American Association of State Highway and Transportation Officials

CSS Context Sensitive Solutions 

FDOT Florida Department of Transportation

FHWA Federal Highway Administration

HCM Highway Capacity Manual

HSM Highway Safety Manual

MPO Metropolitan Planning Organization

NACTO National Association of City Transportation Officials

NCHRP National Cooperative Highway Research Program

PBPD Performance-Based Practical Design 

PBPP Performance-Based Planning and Programming

TSMO Transportation System Management and Operations

TWLTL Two-way left-turn lane
Overview and Purpose of the Primer

11

Operations in Performance-Based Practical Design: A Primer on Complete Streets

OVERVIEW AND PURPOSE

OF THE PRIMER 

Urban streets must serve many types of users and 

trips, and the right-of-way for the street is often fixed 

due to surrounding development. In recent years there 

has been an increased desire by agencies to better 

serve all users of urban streets, regardless of mode of 

travel. The Complete Streets design principles seek 

to better share the limited street right-of-way among 

multiple users while enhancing the livability of the 

street for adjacent residents. (Reference 1)

This Primer describes the principles of PerformanceBased Practical Design (PBPD) and shows how 

PBPD and Transportation System Management and 

Operations (TSMO) strategies can be employed to 

produce Complete Street designs that better meet the 

needs of travelers and achieve agency policies, goals, 

and objectives under a wider range of traffic contexts.

PBPD modifies the traditional “top-down, standardsfirst” approach to a “design up” approach in which 

designers and decision-makers exercise engineering 

judgment to build up the roadway and operational 

improvements from existing conditions to meet both 

project and system objectives. PBPD uses appropriate 

analysis tools to evaluate the performance impacts of 

planning and design decisions in relation to the cost of 

providing various geometric elements and operational 

features.

TSMO—also often referred to simply as “operations”—

is a set of “integrated strategies to optimize the 

performance of existing infrastructure through the 

implementation of multimodal and intermodal, crossjurisdictional systems, services, and projects designed 

to preserve capacity and improve security, safety, and 

reliability of the transportation system.” (Reference 2)

Complete Streets “are streets for everyone.” “They 

are designed and operated to enable safe access for 

all users, including pedestrians, bicyclists, motorists 

and transit riders of all ages and abilities.” (Reference 

3) Typical elements that make up a complete street 

include “sidewalks, bicycle lanes (or wide, paved 

shoulders), shared-use paths, designated bus lanes, 

safe and accessible transit stops, and frequent and 

safe crossings for pedestrians, including median 

islands, accessible pedestrian signals, and curb 

extensions.” (Reference 1)

PBPD is the guiding principle for costeffective design. TSMO is a set of low 

capital cost solutions that the designer 

can employ to increase the success of 

his or her design or can consider as a 

complete design alternative.

COMPLETE

STREETS

PBPD TSMO

Figure 1. Diagram. Performance-Based Practical

Design + Transportation Systems Management and 

Operations -> Better Complete Streets.
U.S. Department of Transportation | Federal Highway Administration

12

Overview and Purpose of the Primer

Figure 2. Photo. Complete Street Example.

(Source: Reference 1)

Figure 3. Photo. Example Complete Street Result.

(Source: Reference 1)

Unless one is designing a new street in an 

undeveloped area, the designer is usually 

confronted with all of the right-of-way and 

design constraints of retrofitting a Complete 

Street design onto an existing street crosssection. For low volume and low speed 

streets (under 20,000 average annual daily 

traffic (AADT) and under 35 mph), many of 

the design tradeoffs (narrow lanes, reduced 

lanes, adding bike lanes, etc.) are easy 

to make, requiring little formal trade-off 

analysis. The challenge comes in retrofitting 

Complete Street concepts on a higher 

volume or higher speed street. That is where 

the more-formal trade-off analysis implicit 

in the PBPD process comes into play. TSMO 

can assist the designer through the PBPD 

process by increasing the number of design 

solutions available to the designer and by 

supporting the success of those design 

solutions.
Chapter 1 Complete Streets: Description and Design Considerations

13

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Complete Streets are literally streets designed for 

use by everyone. “They are designed and operated to 

enable safe access for all users, including pedestrians, 

bicyclists, motorists and transit riders of all ages and 

abilities.” (Reference 3)

“Typical elements that make up a complete street 

include: sidewalks, bicycle lanes (or wide, paved 

shoulders), shared-use paths, designated bus lanes, 

safe and accessible transit stops, and frequent and 

safe crossings for pedestrians, including median 

islands, accessible pedestrian signals, and curb 

extensions.” “The common denominator is balancing 

safety and convenience for everyone using the road.” 

(Reference 1)

A Complete Street design is shown in Figure 4. 1

 The 

Elizabeth Street (in Charlotte, North Carolina) rightof-way was originally able to accommodate four 

travel lanes without on-street parking plus sidewalks 

with a landscaped buffer. The figure shows the results 

of a Complete Streets design concept application 

with a Road Diet reducing Elizabeth Street to two 

motor vehicle travel lanes, with bus and rail transit 

service sharing the motor vehicle traveled way, 

1 Note that every Complete Street design must balance several competing 

objectives. In the example in this photo the street car tracks improve transit 

mobility, but by being placed adjacent to the bike lanes they may limit the 

ability of bicyclists to maneuver around debris in the bike lane. Increased 

monitoring and maintenance (TSMO) may reduce this issue.

on-street parking for motor vehicles, pedestrians in 

sidewalks that are separated from the traveled way 

by landscaped buffers (new street trees in bulb-outs, 

grass, and densely spaced street light poles on both 

sides of the street), and bicycles in the bike lanes 

adjacent to the traveled way.

Chapter 1 Complete Streets: Description and Design Considerations

Source: Kittelson & Associates, Inc.

Figure 4. Photo. Prototype Complete Street.

(Source: Reference 1)
U.S. Department of Transportation | Federal Highway Administration

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Chapter 1 Complete Streets: Description and Design Considerations

DESIGN AND OPERATIONAL 

COMPONENTS OF COMPLETE 

STREETS

The design components of a Complete Street design 

include traffic and speed control, pedestrian, bicycle, 

and transit treatments.12 Operational components may 

be included in the design treatments to ensure their 

success.

• Traffic and Speed Control Design Treatments 

may include: speed humps, bulb-outs/chokers, 

chicanes, diverters, closures, roadway narrowing, 

mini roundabouts, roundabouts.

• Pedestrian Design Treatments may include: refuge 

islands, sidewalk widening, crosswalks, midblock 

crosswalks.

• Bicycle Design Treatments may include: bike 

boulevards/neighborhood greenways, shared lane 

markings, bike lanes, separated bike lanes, onstreet parking removal.

• Transit Design Treatments may include: bulb outs 

at transit stops, bus turnouts (bus pullouts or bus 

bays), exclusive transit lanes, queue jump lanes.

• Operational components of the design may 

include: signal-timing improvements (such as 

pedestrian crossing times, cycle lengths, green 

times, coordination), speed limit reductions, traffic 

enforcement, transit priority at the signals, signal 

coordination timed for transit, bicycle detection 

at signals, real-time transit arrival information, and 

“smart” parking management systems.

A crucial consideration in the design of a Complete 

Street is determining the target design speed and 

traffic volumes for the street. Unlike conventional 

road design practices, which design the road to 

accommodate the predicted traffic volumes and 

speeds, a Complete Street design approach treats 

traffic volumes and speeds as additional design 

parameters to be evaluated within the design process 

as design alternatives.23

2 Note that not all of these design components are compatible with each 

other, nor may they be appropriate under differing traffic volumes and speeds. 

Some may be appropriate for a low volume street but not for a higher volume 

street.

3 Consult the NACTO Urban Street Design Guide (Reference 4) for more 

details on design components and operational strategies.

 4 Land use is a consideration in addition to roadway classification, as noted in 

the next major bullet point.

Design considerations to be taken into account in 

setting design objectives and making design decisions 

should include:

Roadway Classification System and Street Types 4

• Higher class roadways (such as major arterials) 

may have a different appropriate balance 

between mobility and accessibility objectives.

• A suburban arterial will have different mobility 

and accessibility objectives than an urban street.

Fronting Land Uses

• The adjacent land uses to the street will 

determine the relative needs for auto, transit, 

bicycle, and pedestrian accessibility.

• Driveway density may impact the design options 

and objectives.

Design and Posted Speed

• The agency objectives for the street should vary 

according to the roadway class, the street type, 

and fronting land uses. These objectives will in 

turn drive the selection of the design speed and 

the posted speed limit for the street. The design 

speed affects many of the design and operation 

decisions for a Complete Street design.

Traffic Volumes

• The street volumes and turning patterns 

should be considered in the Complete Street 

design process. In general, four-lane, undivided 

roadways begin to operate in a manner similar 

to a three-lane roadway as the number of access 

points and left-turn volumes increase. In this 

situation, the four-lane, undivided roadway begins 

to operate as a de facto three-lane roadway 

and the operational impacts of a Complete 

Street design that reduces through lanes may be 

smaller.

Design Vehicles

• Selecting the design vehicles to be used for 

a Complete Street design is an agency policy 

decision and may not necessarily be the same 

choices as would be made for other types of 

highway projects.
Chapter 1 Complete Streets: Description and Design Considerations

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Operations in Performance-Based Practical Design: A Primer on Complete Streets

Intersections

• Intersection design treatments and intersection 

controls are key design decisions. Signalized 

intersections are often the capacity “pinch points” 

along a street. Making intersection improvements 

in conjunction with a Complete Street may 

minimize adverse operational impacts.

Parking

• Whether or not and to what extent on-street 

parking must be accommodated in the Complete 

Street design is a key agency policy decision.

Pedestrian, Bicycle, and Public Transportation Use

• The consideration and targeting of the design 

to encourage more-extensive transit bicycle and 

pedestrian use is a key design decision.

THE DESIGN OBJECTIVE: MAKING 

IT FIT, BALANCING NEEDS

The basic design objective when following Complete 

Streets design principles is to balance the safety and 

performance of the street for all modes of travel within 

a constrained street right of way. Many safety, mobility, 

and accessibility tradeoffs must be considered and 

weighed to achieve the solution that best meets the 

objectives of the agency. Some of the key design 

decisions to be made are:

1. Can the multimodal safety and accessibility goals 

of the agency for the Complete Street project be 

better achieved with lower speeds, fewer lanes, 

and narrower motor vehicle travel lanes?

2. Can some of the potential adverse impacts of 

fewer lanes and narrow lanes be partially or 

completely mitigated through the application 

of transportation system management and 

operations (TSMO) strategies? If so, which TSMO 

strategies are the most cost-effective at achieving 

the project goals?

3. Which enhancements to the transit accessibility, 

bikability, and walkability of a street can best 

achieve the agency’s short- and long-term safety, 

accessibility, and livability goals for the project and 

for the street system?

Performance-Based Practical Design supplemented 

with operations strategies can assist the designer in 

arriving at the best solution through a series of logical 

and defensible design decisions.

FURTHER READING ON 

COMPLETE STREETS DESIGN

The following references can be consulted for 

more information on the design components and 

considerations of Complete Streets:

• American Planning Association, “Complete Streets: 

Best Policy and Implementation Practices”, 2010.

• FHWA, “Road Diet Informational Guide”, FHWASA-14-028, 2014.

• “Complete Streets Design Manual,” Smart Growth 

America.

• “Urban Street Design Guide,” National Association 

of City Transportation Officials.

• “Statewide Lane Elimination Guide,” Florida 

Department of Transportation, 2014.

• FHWA, “Incorporating On-Road Bicycle 

Networks into Resurfacing Projects,” 2016.FHWA, 

“Workbook for Building On-Road Bike Networks 

through Routine Resurfacing Programs”, 2016 

http://www.fhwa.dot.gov/environment/bicycle_

pedestrian/publications/resurfacing/resurfacing_

workbook.pdf

• New York City Department of Transportation, 

“Street Design Manual”, 2015 http://www.

nyc.gov/html/dot/downloads/pdf/nycdotstreetdesignmanual-interior-lores.pdf

• Los Angeles County, “Model Design 

Manual for Living Streets”, 2011 http://

modelstreetdesignmanual.com/model_street_

design_manual.pdf

• Charlotte Department of Transportation, “Urban 

Street Design Guidelines”, 2007 http://charmeck.

org/city/charlotte/Transportation/PlansProjects/

pages/urban%20street%20design%20guidelines.

aspx

Chapter 2 Performance-Based Practical Design

17

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Performance-Based Practical Design (PBPD) 

in combination with Transportation System 

Management and Operation (TSMO) strategies can 

assist planners and engineers in arriving at the best 

design and operations solution through a series of 

logical and defensible design decisions. 

PERFORMANCE-BASED 

PRACTICAL DESIGN

PBPD modifies the traditional “top-down, standardsfirst” approach to a “design up” approach in 

which designers and decision-makers exercise 

engineering judgment to build-up the roadway and 

operational improvements from existing conditions 

to meet both project and system objectives. 

PBPD uses appropriate analysis tools to evaluate 

the performance impacts of planning and design 

decisions in relation to the cost of providing various 

geometric elements and operational features.

PBPD should not be viewed as a stand-alone 

set of activities. Rather, it is an integral part of a 

broader process known as “Performance-Based 

Planning and Programming.” The FHWA publication 

“Performance-Based Planning and Programming 

Guidebook” (Reference 5) describes the application 

of performance management principles within 

the planning and programming processes of 

transportation agencies and regional entities (e.g., 

MPOs) to achieve desired performance outcomes for 

the multimodal transportation system. Figure 5 shows 

the Performance-Based Planning and Programming 

(PBPP) process, indicating where PBPD concepts 

and activities may be applied. As shown in Figure 

5, PBPD-related activities can be applied to the 

preliminary engineering and design activities, with 

any cost savings going to support additional projects 

as part of the regional programming process. PBPD 

concepts can also be used during planning activities 

to help identify strategies and analyze alternatives.

Figure 6 identifies and summarizes the various 

PBPD concepts and potential activities, starting 

with “baseline conditions” including design policies 

and guidelines, current and projected issues and 

needs, and stakeholder concerns; then moving into 

analysis such as developing alternatives, analyzing 

these alternatives in terms of improved performance 

and costs, coupled with trade-offs and engineering 

judgment. The results of these PBPD-related activities 

and concepts (i.e., “Moving Forward”) is the selection 

of the optimal concepts and strategies for design, 

the identification of any design exceptions, and the 

documentation of the decisions.

Chapter 2 Performance-Based Practical Design

Source: Kittelson & Associates, Inc.
U.S. Department of Transportation | Federal Highway Administration

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Chapter 2 Performance-Based Practical Design

As collectively shown in Figure 5 and Figure 6, PBPD 

designers apply a “design up” approach by using 

existing conditions as the baseline and engineer 

solutions that meet the project purpose based 

on explicitly defined transportation performance 

needs as derived from system and regional goals 

and objectives. This approach differs from a moreconventional approach of setting project design 

criteria based solely on values listed in design 

specifications or standards for a set of given 

conditions. Designers then evaluate the solutions 

against the tradeoffs based on an objective analysis 

of performance data. Some of the tradeoffs 

considered include the estimated costs for each 

potential solution, coupled with due consideration 

of agency polices, legal requirements, stakeholder 

sensitivities, and any other potential constraints. 

Figure 5. Diagram. Framework for Performance-Based Planning and Programming.

(Source: Adapted from Reference 5)
Chapter 2 Performance-Based Practical Design

19

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Figure 6. Diagram. Concepts and Activities Associated with Performance-Based Practical Design.

(Figure is based on several Federal Highway Administration documents and

presentations on the subject of Performance-Based Practical Design)
U.S. Department of Transportation | Federal Highway Administration

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Chapter 2 Performance-Based Practical Design

A basic tenet of PBPD involves making project 

decisions that directly serve performance needs while 

considering whether the same investment of money 

would yield a greater return on investment if applied 

to other system needs and/or priorities. It is important 

to document the design decisions and present them 

to decision makers showing the benefits relative to 

the no-build option. These PBPD design and decisionmaking analyses can easily be transferred to design 

exception forms for review, approval and recordkeeping.

By implementing a PBPD approach, agencies 

may reduce or eliminate project elements that are 

determined to be non-essential, resulting in lower cost 

and improved value by taking advantage of existing 

design flexibility. Agencies may also use the associated 

cost saving to deliver a greater number of projects 

that yield a greater performance return on investment 

than otherwise possible under existing project 

development and design approaches.

Relationship between Performance-Based 

Practical Design and Context-Sensitive Solutions

Context-Sensitive Solutions (CSS) seek a 

transportation solution that addresses the needs of all 

road users and the functions of the facility within the 

context of its setting, considering land use, users, the 

environment, and other factors. CSS is a collaborative, 

interdisciplinary approach that includes the viewpoints 

of all stakeholders in the development of a shared 

vision of project goals, and uses a defined decisionmaking process. CSS and PBPD rely on flexibility 

to achieve results that meet the project purpose 

and need. PBPD compliments CSS by providing 

performance information that supports decisionmaking.

Design Criteria and Design Exceptions

As previously noted, PBPD moves away from the 

more-conventional “top-down, standards-first” 

approach to a more performance- and value-based 

“design up” approach. Designers that focus on 

the relationships between design dimensions and 

performance may become less obligated to meet one 

or more of the design guidelines, such as those found 

in the AASHTO Green Book (“A Policy on Geometric 

Design of Highways and Streets”). Design criteria and 

standards offer many benefits, including promoting 

consistency, establishing a design “norm,” and 

promoting efficiency in design development. 

However, “standard” does not necessarily mean 

“best,” nor are standards intended to be a substitute 

for engineering judgment and context-specific 

considerations.

Federal regulations (Reference 6) state that “Approval 

...may be given on a project basis to designs which do 

not conform to the minimum criteria as set forth in the 

standards, policies, and standard specifications.” A 

design exception is a documented decision to design 

a highway element or a segment of highway to design 

criteria that do not meet minimum values or ranges 

established for that highway or project. A design 

exception is NOT an indication of failure or a “flawed” 

design; rather, it is a necessary and legitimate process 

to allow professional and engineering judgment in the 

design process, providing a useful “tool” for employing 

practicality and flexibility in design decisions in a 

design-up approach such as PBPD.

As noted in the FHWA document “Mitigation 

Strategies for Design Exceptions” (Reference 7) there 

are a broad range of reasons why design exceptions 

may be considered and found to be necessary. Some 

of these include the following:

• Impacts to the natural environment

• Social or right-of-way impacts

• Preservation of historic or cultural resources

• Sensitivity to context

• Sensitivity to community values

• Construction or right-of-way costs

A final notice published in the Federal Register on 

May 5, 2016 (Reference 8) completed FHWA’s effort 

to update the policy regarding controlling criteria for 

design, applicable to projects on the National Highway 

System. FHWA reduced the number of controlling 

criteria from 13 to 10 for Interstate highways, other 

freeways, and roadways with design speed ≥ 50 mph, 

and now applies only two of those criteria to low 

speed roadways (non-freeways with design speed <50 

mph). FHWA also clarified when design exceptions are 

needed and the documentation that is expected to 

support such requests.

FHWA has adopted new policies to modify highway 

design standards that encourage greater flexibility in 

order to achieve a design that best suits the desires of 

the community, while satisfying the purpose for the 

project and needs of its users. As an example, FHWA 

published revisions to current federal policy that will 

help reduce cost and speed up the design of local
Chapter 2 Performance-Based Practical Design

21

Operations in Performance-Based Practical Design: A Primer on Complete Streets

roads and streets. In 1985, thirteen design criteria 

were prioritized because of their perceived impact 

on operations and safety. Under the new policy, ten 

criteria will be prioritized for high speed roadways, and 

only two criteria will be emphasized for lower-speed 

roads such as rural roads that become main streets 

through smaller towns and cities. This will provide 

state and local engineers to develop flexible design 

solutions that meet local travel needs and goals.

TRANSPORTATION SYSTEMS 

MANAGEMENT AND OPERATIONS

Transportation Systems Management and 

Operations (TSMO)—also often referred to simply as 

“operations”—is defined as:

“Integrated strategies to optimize the performance 

of existing infrastructure through the implementation 

of multimodal and intermodal, cross-jurisdictional 

systems, services, and projects designed to preserve 

capacity and improve security, safety, and reliability of 

the transportation system.”

Intelligent Transportation System (ITS) technologies 

are crucial to the success of these operations 

strategies. ITS technologies include: devices for 

monitoring traffic flow on the roadways, hardware 

and software at transportation management centers 

(TMCs), and/or “Connected Vehicle” applications. ITS 

represents the “enabling technology for operations.”

TSMO strategies—coupled with the supporting 

ITS technology—are a most-important aspect of 

delivering transportation services to customers. 

Experience has shown that aggressive applications 

of these operations strategies can, in effect, “take 

back” much of the capacity lost due to congestion 

and disruptions. Operations strategies also enhance 

safety, promote reduced emissions, and increase 

system reliability. Perhaps most importantly, actively 

managing the transportation network can improve 

travelers’ experiences, providing them with realtime information and choices throughout the trip 

chain—from origin to destination—leading to network 

performance optimization and increased efficiency. 

TSMO strategies are relatively low cost (compared 

with adding capacity), much quicker to implement 

(two to three years), and offer substantial benefits 

(with very positive benefit-cost ratios).

FHWA recommends an “objectives-driven, 

performance-based approach” for including 

“operational and management strategies to improve 

the performance of existing transportation facilities” 

in the planning process. This objectives-driven, 

performance-based approach to planning for 

operations within a metropolitan area—conducted 

in collaboration among planners, transportation 

providers, operators, and other stakeholders—is shown 

in Figure 7.

The activities shown in Figure 7 parallel the PBPD 

process—including the development of potential 

strategies based on goals, objectives, and needs; 

then, evaluating and subsequently selecting strategies 

in terms of performance and cost. Moreover, lowcost, rapidly deployable, and flexible treatments—as 

provided by many TSMO strategies—all fall under the 

umbrella of PBPD. 

Controlling Criteria for Design 

Exceptions, 2016

1. Design Speed*

2. Lane Width

3. Shoulder Width

4. Horizontal Curve Radius

5. Superelevation

6. Maximum Grade

7. Stopping Sight Distance

8. Cross Slope

9. Vertical Clearance

10. Design Loading Structural Capacity*

* Design Speed and Design Loading Structural 

Capacity apply to all roads on the National 

Highway System
U.S. Department of Transportation | Federal Highway Administration

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Chapter 2 Performance-Based Practical Design

Figure 7. Flowchart. An Objectives-Driven, Performance-Based Approach.

(Adapted from References 9 and 10)
Chapter 3 Employing (PBPD) and (TSMO) in Designing Complete Streets

23

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Developing Complete Street designs for low-volume, 

low-speed streets (e.g. under 20,000 AADT and 

speed limits under 35 mph) requires little in the way 

of formal performance trade-off analyses. However, 

as one approaches or exceeds these limits the 

feasibility of Complete Street design principles comes 

into question. The designer is faced with a yes/no 

decision as to whether or not a Complete Street 

design is feasible. The Performance-Based Practical 

Design process with TSMO elements included gives 

planners and designers the tools to develop morenuanced answers to the feasibility question and to 

identify low-cost TSMO strategies that can extend 

the range of feasible application for Complete Street 

concepts.

SETTING THE DESIGN 

OBJECTIVES AND 

PERFORMANCE MEASURES

The first step to employing the PBPD process is to 

identify the agency’s goals for the Complete Street 

project. The agency’s mobility, accessibility, livability 

and safety goals must then be translated into project 

objectives. Each project objective should be assigned 

with a specific performance measure for quantifying 

the achievement of the project objectives for each 

design concept.

One of many possible examples of a “Goals/

Objectives/Measures” PBPD analysis matrix is shown 

in Table 1. Note that more than one performance 

measure may be necessary to accurately measure 

achievement of a given objective, and multiple 

objectives may be relevant to a single goal. An 

agency should construct a matrix that meets its 

needs for assessing alternative design concepts, 

and yet does not require performance analyses 

that exceed the resources and tools available to the 

designer.

IDENTIFYING CANDIDATE 

DESIGN CONCEPTS

Once the project goals, objectives, and performance 

measures have been selected then various design 

concepts are considered to find the practical design 

that best meets the agency’s objectives. The designer 

consults the various design manuals and guides on 

Complete Streets to identify and develop alternative 

design concepts for PBPD analysis. 

 Employing Performance-Practical Design and

 Transportation Systems Management Operations in

Chapter 3 Designing Complete Streets

Source: Kittelson & Associates, Inc.
U.S. Department of Transportation | Federal Highway Administration

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Chapter 3 Employing (PBPD) and (TSMO) in Designing Complete Streets

A few key references are listed here:

• “Complete Streets: Best Policy and 

Implementation Practices”, American Planning 

Association, 2010.

• “Complete Streets Design Manual,” Smart Growth 

America

• “Urban Street Design Guide,” National 

Association of City Transportation Officials.

Additional useful design references for Complete 

Streets are listed at the end of Chapter 1.

Figure 7 and Figure 8 illustrate some example 

bicycle and pedestrian design treatments. FHWA’s 

Separated Bike Lane Planning and Design Guide 

(Reference 11) should be consulted for additional 

examples. Additional pedestrian design treatments 

not shown here include: Pedestrian Hybrid Beacons 

(PHB), pedestrian refuge islands, raised crosswalks, 

crosswalk visibility enhancements, and rectangular 

rapid flash beacons (RRFBs).

Figure 9 illustrates how the project objectives and 

performance measures, once translated into design 

objectives are then used to generate design options. 

In this figure, only one of several potential design 

concepts is shown.

For this particular design concept, the number of 

travel lanes and the widths of the travel lanes are 

reduced in order to provide cross-sectional width 

for new bike lanes dedicated exclusively to bicycles, 

a median buffer (a two-way left turn lane) between 

opposing traffic, a striped buffer between traffic and 

the bike lanes and, a landscaped buffer between 

traffic and pedestrians.

The TSMO strategies listed in the box in the figure 

would enable consideration of this design concept 

for moderately higher volume and speed streets than 

would be feasible in the absence of TSMO strategies.

Agency Goals Maximize System Cost 

Effectiveness

Maximize System 

Safety

Promote 

Sustainability 

Promote 

Livability

Project Objectives Reduce travel times 

and costs by X% 

below existing within 

1 year of project 

opening

Reduce crashes by 

X% from existing 

within 1 year of project 

opening

Reduce greenhouse 

gas vehicle emissions 

by X% from existing 

within 1 year of project 

opening

Increase active mode 

use by X% from 

existing within 1 year 

of project opening

Project Performance 

Measures

Person-hours of delay

Estimated Cost of 

Improvements

Crashes Grams CO2 equivalent 

emitted per day

HCM Bike LOS HCM 

Ped LOS

Example of Meeting 

the Objective 

through Design 

Select design features 

that do not unduly 

increase auto, bus, 

or truck delay at 

best project costeffectiveness. Keep 

v/c ratio below 1.00.

Increase buffers 

between opposing 

traffic and between 

traffic and non-motor 

vehicle modes.

Select design 

features that reduce 

attractiveness of 

street for high speed 

auto use.

Select design features 

that encourage 

walking and bicycling.

Table 1. Example: Performance-Based Practical Design Performance Analysis Matrix.

HCM = Highway Capacity Manual. LOS = Level of Service
Chapter 3 Employing (PBPD) and (TSMO) in Designing Complete Streets

25

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Figure 8. Chart. Levels of Separation of Bicycle Treatment Options.

(Source: Reference 11)

Signed Routes (No Pavement Markings)

A roadway designated as a preferred

route for bicycles.

Shared Lane Markings

A shared roadway with pavement markings

providing wayfinding guidance to bicyclists and

alerting drivers that bicyclists are likely to be 

operating in mixed traffic.

On-Street Bike Lanes

An on-road bicycle facility designated by 

striping, signing, and pavement markings.

On-Street Buffered Bike Lanes

Bike lanes with a painted buffer increase

lateral separation between bicyclists and

motor vehicles.

Separated Bike Lanes

A separated bike lane is an exclusive facility

for bicyclists that is located within or directly

adjacent to the roadway and that is physically

separated from motor vehicle traffic with a 

vertical element.

Off Street Trails / Sidepaths

Bicycle facilities physically separated from 

traffic, but intended for shared uses by a variety 

of groups, including pedestrians, bicyclists, and 

joggers.

Most

Separation

Least

Separation
U.S. Department of Transportation | Federal Highway Administration

26

Chapter 3 Employing (PBPD) and (TSMO) in Designing Complete Streets

First Avenue, New York City

First Avenue South, St. Petersburg, Florida

Figure 9. Photos. Additional Bicycle and Pedestrian Design Treatment Examples.

(Source: Reference 11)
Chapter 3 Employing (PBPD) and (TSMO) in Designing Complete Streets

27

Operations in Performance-Based Practical Design: A Primer on Complete Streets

TSMO Strategies to Enhance 

Achievement of Project Objectives

• Lowered speed limit to improve 

safety.

• Added left turn pockets at major 

signalized intersections for capacity.

• Revised signal timing at 

intersections to compensate for lost 

through capacity.

• Added bicycle detectors at signals.

• Added bicycle box left turns for 

safety.

Figure 10. Diagrams. Application of Performance-Based Practical Design to Generate 

One of Many Potential Complete Street Design.
U.S. Department of Transportation | Federal Highway Administration

28

Chapter 3 Employing (PBPD) and (TSMO) in Designing Complete Streets

ROLE OF TRANSPORTATION 

SYSTEM MANAGEMENT 

OPERATIONS IN COMPLETE 

STREETS

Complete Streets sometimes involve reducing motorvehicle travel lanes, which may increase delays due 

to motor-vehicle congestion and reduce auto, truck, 

and bus speeds on the street.15 Complete Streets 

may also narrow the travel lanes to make room 

for additional safety buffers on the street. TSMO 

strategies can augment achievement of the design 

objectives of Complete Streets. Table 2 provides 

some illustrative examples of TSMO strategies 

targeted to specific design objectives. The text below 

describes some of these strategies in more detail. 

The reader should consult the FHWA TSMO primer 

(Reference 12) and the AASHTO Guidance (Reference 

5 A common misconception is that reducing the number of through lanes 

(a Road Diet) will cause traffic to become more congested. However, when 

applied correctly in the right locations, a Road Diet can still maintain a 

roadway’s effective capacity. For example, when a corridor contains a large 

number of access points (driveways) the majority of through traffic will tend to 

utilize the outside lanes to avoid being delayed by left-turning vehicles slowing 

and stopping in the inside lanes. These four-lane corridors essentially behave 

like a three-lane road (one through lane in each direction and one two-way 

left turn lane). Thus, when a Road Diet is installed and reconstructed to a 

three-lane section, the roadway is unlikely to experience a change in capacity. 

A PBPD analysis of the traffic performance of the design concept can reveal 

conditions when capacity is maintained or lost.

13) for a more-complete list of TSMO strategies and 

additional information on their effects on operations 

and safety. TSMO strategies for reducing motor 

vehicle speeds, and especially TSMO strategies that 

reduce the differential between high and low speed 

vehicles include:

• Signal coordination plans that favor a lower 

target speed for motor vehicles that is more 

compatible with the multimodal safety objectives 

of Complete Streets.

• Lower posted speed limits

• Radar speed advisory signs.

• Automated speed enforcement (where enabling 

legislation is in place)

• Automated red light enforcement (where 

enabling legislation is in place)

Operational Objective Geometric

TSMO Strategies

Control

TSMO Strategies

Other

TSMO Strategies

Lower Traffic Speeds to 

Improve Safety

• Pavement surface 

treatments

• Speed Humps

• Lower Speed Limit

• Lower Signal 

Progression Speed

• Radar Speed Advisory 

Signs

• Automated Speed 

Enforcement

Reduce Crashes • Access Management.

• Consolidated driveways

• Review traffic and ped 

clearance intervals.

• Improve signal head 

visibility.

• Review mid-block ped 

crossings.

• Automated red light 

enforcement.

• Ped HAWK beacon.

• Higher intensity street 

lighting

• Bicycle boxes

Preserve Traffic Capacity 

to maintain bus, truck, and 

auto speeds

• Turn pockets at signals • Change signal timing

• Adaptive signal timing

• Bus Signal Priority

• Bus/bike queue jumps

• Weather management 

and response (snow 

removal).

Table 2. Example: Applications of Transportation Systems Management Operations Strategies to Support 

Performance-Based Practical Design in Complete Streets.

This table is intended to be illustrative of some of the TSMO strategies that may be employed. See the FHWA 

Primer on TSMO and AASHTO Guidance for more information.
Chapter 3 Employing (PBPD) and (TSMO) in Designing Complete Streets

29

Operations in Performance-Based Practical Design: A Primer on Complete Streets

TSMO strategies can be a means to reinforce 

achievement of the Complete Street objectives 

to enhance multimodal safety and convenience. 

Examples include:

• Bike and Transit queue jump lanes

• Pedestrian scramble, diagonal crossing phase

• Passive pedestrian sensors that activate 

pedestrian warning signs/lights (for example 

HAWK beacons) for unsignalized pedestrian 

crossings

• Weather management and response strategies 

(snow clearance)

TSMO strategies can enhance the motor-vehicle 

capacity of a specific Complete Street design 

concept. Examples of capacity-enhancing TSMO 

strategies include:

• Re-timing the traffic signals to give higher green 

times per cycle (g/c) to the street approach with 

the reduced motor-vehicle travel lanes.

• Increasing the cycle length to provide more 

overall capacity at the intersection (lost time per 

hour during amber and all-red change intervals is 

reduced when there are fewer cycles per hour).16

• Adding left- and right-turn pockets at an 

intersection so that lower capacity turns can be 

made outside of the through lanes.27 (These 

pockets should be considered carefully, because 

they might increase pedestrian crossing times, 

distances and conflicts, thus reducing some 

of the other pedestrian safety benefits of the 

design).

• Dropping on-street auto parking on the 

approaches and exits to a signal so that an 

additional through lane can be maintained for 

several hundred feet before and after the signal.

• Transit queue jump lanes with dynamic transit 

signal priority on the approach to the signal 

may enable buses to avoid the motor-vehicle 

congestion effects of fewer travel lanes on the 

street.

6 Note however, that increasing cycle lengths will usually increase average 

delay for all users of the street

7 Note that left turn pockets are a natural outcome of a road diet employing a 

Two-Way Left Turn Lane.

There are also institutional and policy considerations 

to take into account when developing Complete 

Street designs. The FHWA Guide: “The Role of 

Transportation Systems Management & Operations 

in Supporting Livability and Sustainability: A Primer,” 

provides information on how TSMO strategies can 

support livability and sustainability policies.

FURTHER READING ON 

TRANSPORTATION SYSTEM 

MANAGEMENT AND OPERATIONS 

STRATEGIES

The following references can be consulted for more 

information on TSMO strategies for supporting a 

Complete Street design.

• FHWA, “Designing for Transportation 

Management and Operations: A Primer,” 

FHWA HOP-13-013, available at National 

Operations Center of Excellence: http://www.

transportationops.org/publications/designingtransportation-management-and-operationsprimer-0

• FHWA, “Regional Concept for Transportation 

Operations,” FHWA-HOP-07-122, available at: 

http://ops.fhwa.dot.gov/publications/rctoprimer/

prim0701.htm

 

• FHWA, “Creating an Effective Program to 

Advance Transportation System management 

and Operations, a Primer”, FHWA-HOP-12-003, 

available at: http://ops.fhwa.dot.gov/

Publications/fhwahop12003/background.htm

• AASHTO, Transportation Systems Management 

and Operations (TSMO), available at http://www.

aashtoTSMOguidance.org/

• FHWA, The Role of Transportation Systems 

Management & Operations in Supporting 

Livability and Sustainability: A Primer, FHWAHOP-12-004, January 2012. Available at: 

http://www.ops.fhwa.dot.gov/publications/

fhwahop12004/fhwahop12004.pdf 
U.S. Department of Transportation | Federal Highway Administration

30

Chapter 4 Analyzing the Tradeoffs
31

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Chapter 4 Analyzing the Tradeoffs

Once the candidate design concepts have been 

identified, the next step in the Performance-Based 

Practical Design (PBPD) analysis process is to quantify 

how the design concepts affect performance, and 

ultimately achievement of the project objectives. If one 

option includes reconfiguring the roadway to include 

a two-way, left-turn lane to the street, how much does 

that increase safety? What affect will fewer and/or 

narrower lanes have on traffic operations, pedestrian 

and bicycle safety, and motor vehicle crash rates?

 

This chapter provides a brief summary of what is 

known about the relationships between Complete 

Streets and the typical project objectives of reducing 

crashes, avoiding excessive delays to transit service, 

and increasing the use of the street by pedestrians 

and bicyclists. The analyst is then referred to various 

national references to obtain more specifics on the 

available analysis methods and tools.

Complete Street design concepts may reconfigure 

through traffic lanes. They may also narrow motorvehicle travel lanes to secure additional safety buffers 

between motorized and non-motorized modes using 

the street.18 

8 Narrow lanes generally have little to no capacity or speed effect on low 

speed streets (speed limits under 35 mph).

These design decisions may:

• Adversely affect bus transit, rail transit, and trucks 

using the street (unless transit is given exclusive 

lanes on the street). 

• Encourage through traffic (including trucks) to 

divert to other streets. 

• Reduce the potential conflicts between motorized 

and non-motorized users of the streets. 

• Reduce number and severity of crashes, and 

especially bicycle and pedestrian involved crashes 

on the street.

LANE WIDTHS – OPERATIONAL 

EFFECTS ON MOTOR VEHICLES

The impacts of lane widths (in the range of 10 to 12 

feet) vary according to the free-flow speed of the 

street. High speed streets (with free-flow speeds 

greater than 35 mph) generally are more sensitive to 

narrow lane widths than low-speed streets.

Moderate- to Low-Speed Streets. Signalized 

intersections generally dictate the capacity of an 

urban street (a street with traffic signals spaced no 

more than two miles apart). As shown in Table 3, lane 

widths in the range of 10 feet to 12 feet generally have 

little effect on the capacity of a traffic signal (Exhibit 

18-13 of Reference 14).

Chapter 4 Analyzing the Tradeoffs

Source: Kittelson & Associates, Inc.
U.S. Department of Transportation | Federal Highway Administration

32

Chapter 4 Analyzing the Tradeoffs

Average Lane Width (feet) Effect on Capacity

<10.0 4% reduction

≥10.0-12.9 0% (no change)

≥12.9 4% increase

Table 3. Lane Width Adjustment Factors for Urban Signalized Intersections.

(Adapted from Exhibit 18-13 of Reference 14)

As indicated by the HCM 2010 adjustment factors in 

Table 3, the reduction of lane widths below 10 feet is 

associated with a reduction in capacity of four percent 

at signalized intersections on urban streets. Wide 

lanes, over 12.9 feet, are associated with the opposite 

effect, an increase in capacity of four percent. There 

may also be speed effects with exceptionally wide 

lanes (greater than 12.9 feet), but these effects are not 

documented for low- to moderate-speed streets.

Lane widths in the 10 to 12 foot range have not been 

identified in the 2010 HCM as a significant factor 

influencing traffic speeds in between intersections 

(for signal controlled streets with free-flow speeds in 

the 25 mph to 45 mph range).

Moderate to High Speed Streets. Narrow lanes can 

reduce both the free-flow speed and the capacity 

of higher speed roads (those with free-flow speeds 

of 45 mph or higher, and with signals more than two 

miles apart) (see Table 4).

Narrow lanes can reduce the free-flow speed of high 

speed roads by two to seven mph. A reduction of five 

mph in the free-flow speed can reduce the capacity 

of a high-speed highway by about five percent 

(source: page 14-4, 2010 HCM. Reducing the free-flow 

speed from 50 to 45 mph reduces the capacity from 

2,000 passenger cars per hour per lane to 1900.).

LANE WIDTHS – SAFETY

The Highway Safety Manual (HSM) safety 

performance functions for urban and suburban 

arterials are not sensitive to lane width. The available 

research at this time on the effects of narrow lanes 

on crashes on urban streets is mixed. In some cases, 

narrow lanes appear to exhibit reduced crash rates. In 

other cases, narrow lanes appear to increase crashes. 

In other cases, a particular width has lower crash 

rates than wider or narrower widths.

There is a National Cooperative Highway Research 

project currently investigating the effects of narrow 

lanes on safety and operations of urban and suburban 

streets (NCHRP 03-112, Operational and Safety 

Considerations in Making Lane Width Decisions on 

Urban and Suburban Arterials), which may bring 

more clarity to the mixed results of previous studies. 

Its estimated completion date is August 2017. The 

following paragraphs highlight the results of available 

research.

The Florida Department of Transportation (FDOT) 

conducted statistical analysis to evaluate the 

impacts of restriping multilane roadways to 

increase the outside lane width by “borrowing” 

width from inner lanes (Reference 16). The crash 

severity and frequency of the imbalanced lanes (i.e., 

asymmetrical) was assessed on four-lane roadways 

with either a flush, two-way left-turn lane (TWLTL) or 

a raised median. 

Lane Width (ft) Reduction in free-flow speed (mi/h) Change in Capacity

>= 12 ft 0.0 0% (no change)

>=11 – 12 ft 1.9 2% reduction

>=10-11 ft 6.6 7% reduction

Table 4. Effects of Narrow Lanes on High Speed Roadway Free-Flow Speed and Capacity.

(Adapted from Exhibit 14-18 of Reference 14)
33

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Chapter 4 Analyzing the Tradeoffs

The study did not differentiate between the width 

of the center TWLTL or raised median. The study 

identified two trends that were statistically significant, 

as follows:

“Given a 24-foot lane width for inside and outside 

through lanes, restriping the outside through lane 

to provide 13-foot lane width and leaving the inside 

lane with 11-foot lane width would result in a slight 

reduction of crashes for four-lane sections with 

raised median.”

“...if an extra 0.5 foot is added to the outside 

asymmetric lane to make it 13.5 feet wide while 

keeping the inside lane at 11 feet, a decrease in 

crashes is found for four-lane sections with raised 

or two-way-left-turn-lane (TWLTL) medians.” 

(Reference 16)

Potts et al. conducted research on the relationship 

between lane width and safety for roadway segments 

and intersection approaches on urban and suburban 

arterials as part of NCHRP Project 3-72: Lane Widths, 

Channelized Right Turns, and Right-turn Deceleration 

Lanes in Urban and Suburban Areas. (Reference 17) 

The research included data from various roadway 

and intersection types in Minnesota and Michigan 

ranging from two-lane, undivided to four-lane, divided 

roadways. They also considered how Average Annual 

Daily Traffic (AADT) and lane width together influence 

safety.

Several trends were observed in the data from 

Minnesota and Michigan, but inconsistencies exist 

between states. The researchers noted that “crash 

frequency in [Minnesota] was higher for 10-foot lanes 

than for 11- and 12-foot lanes on four-lane, undivided 

arterials,” but the same was not true in Michigan. 

They also found that crash frequency in Michigan 

“was higher for 9-foot lanes than for 10-foot lanes on 

four-lane, divided arterials.” The same was not true is 

Minnesota.

The researchers concluded that “...there was no 

indication of an increase in crash frequencies as lane 

width decreased for arterial roadway segments or 

arterial intersection approaches.” They noted the 

inconsistencies between states related to four-lane 

undivided and divided arterials and that, in these 

cases, the inconsistencies should not infer “the use 

of narrower lanes must be avoided.” But, rather the 

inconsistencies indicate that “narrower lanes [must] 

be used cautiously in these situations unless local 

experience indicates otherwise.”

EFFECTS OF LANE 

RECONFIGURATIONS ON 

CAPACITY 

It is possible to reduce the number of travel lanes 

on a street and have no effect on capacity. The 

effect depends on the balance between demand 

and capacity for the different turn and through 

lanes on the streets. A Highway Capacity Manual 

signalized intersection analysis should be conducted 

to determine the capacity effects of a design concept 

and the potential of various TSMO measures (like 

retiming the signal) to boost capacity.

EFFECTS OF COMPLETE STREETS 

ON RELIABILITY

There is no available data on the general effects 

of Complete Streets on motor vehicle travel-time 

reliability. The Sixth Edition of the Highway Capacity 

Manual (Reference 18) does provide a method and tool 

for estimating the change in reliability on a signalized 

street on a case-by-case basis. This tool is a recent 

development and adequate application experience 

using this tool has not yet been obtained to enable 

drawing any general conclusions on the reliability 

effects of Complete Street designs.

COMBINED EFFECTS OF 

COMPLETE STREETS ON SAFETY 

AND MOBILITY

Complete Streets employ a combination of design 

strategies to achieve their goals: reduced lanes, 

narrowed lanes, lower speeds, median buffers 

between opposing traffic flows, buffers between 

motorized and non-motorized users, among many 

other strategies. These individual strategies, when 

employed in combination, have synergistic effects 

greater than (or less than) the effects of each strategy 

alone.

This section consequently presents the results of 

research, before-after studies, and case studies of 

the combined safety and mobility effects of various 

Complete Streets and Road Diets19 that have been 

implemented in practice. 

9 A Road Diet is a design treatment that replaces one or more through traffic 

lanes with other street features designed to improve safety for all users of the 

street (such as two-way-left turn lanes and bike lanes).
U.S. Department of Transportation | Federal Highway Administration

34

Chapter 4 Analyzing the Tradeoffs

Capacity Effects of Complete Streets Employing 

Road Diets

The FHWA summary report, “Evaluation of Lane 

Reduction ‘Road Diet’ Measures on Crashes” 

(Reference 19) noted that: “Under most annual average 

daily traffic (AADT) conditions tested, Road Diets 

appeared to have minimal effects on vehicle capacity 

because left-turning vehicles were moved into a 

common two-way left-turn lane (TWLTL). However, for 

Road Diets with AADTs above approximately 20,000 

vehicles, there is an increased likelihood that traffic 

congestion will increase to the point of diverting traffic 

to alternative routes.”

Safety Effects of Complete Streets Employing 

Road Diets

The same FHWA summary report, “Evaluation of 

Lane Reduction ‘Road Diet’ Measures on Crashes” 

(Reference 19), re-evaluated two prior studies of the 

safety effects of Road Diets that involved changing 

four-lane, undivided highways into two-lane highways 

with a median two-way, left-turn lane (TWLTL). One 

study evaluated 30 treatment sites and 51 reference 

sites in eight cities in California and Washington. 

The other study looked at 15 treatment sites and 15 

reference sites in small towns in Iowa.

The report found significant differences in the safety 

effects observed in the two studies but noted that: 

“These differences may be a function of traffic 

volumes and characteristics of the urban environments 

where the Road Diets were implemented. The sites in 

Iowa ranged in AADT from 3,718 to 13,908 and were 

predominately on U.S. or State routes passing through 

small urban towns with an average population of 

17,000. The sites in Washington and California ranged 

in AADT from 6,194 to 26,376 and were predominately 

on corridors in suburban environments that 

surrounded larger cities with an average population 

of 269,000. In addition, based on a separate study of 

one site in Iowa, there appeared to be a traffic calming 

effect that resulted in a 4–5 mi/h reduction in 85th 

percentile free-flow speed and a 30-percent reduction 

in the percentage of vehicles traveling more than 5 

mi/h over the speed limit (i.e., vehicles traveling 35 

mi/h or higher).”

The report concludes that a 47 percent reduction 

in crashes might be expected for Road Diets 

implemented in conditions similar to those of the Iowa 

sites. A lower 19 percent reduction in crashes might be 

expected for Road Diets implemented in conditions 

more similar to those of the Washington and California 

sites. If the proposed Road Diet treatment site does 

not match any of the Iowa, Washington or California 

site conditions, then an average 29% crash reduction 

might be expected.

FURTHER READING ON SAFETY 

AND MOBILITY EFFECTS

• 2010 Highway Capacity Manual, Transportation 

Research Board, 2010

• Highway Capacity Manual, 6th Edition, 

Transportation Research Board, 2016

• Highway Safety Manual, AASHTO, 2014

• FHWA, Road Diet Informational Guide, (FHWASA-14-028), 2014, http://safety.fhwa.dot.gov/

road_diets/info_guide/ , Accessed January 13, 

2016.

• Evaluation of Lane Reduction “Road Diet” 

Measures on Crashes” (FHWA-HRT-10-053, HRDS06/06-10(1M)E)
35

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Chapter 5 Case Studies

This chapter presents four case studies illustrating the 

application of Performance-Based Practical Design 

(PBPD) concepts to the development of Road Diets 

and Complete Street designs. The first three case 

studies illustrate the application of PBPD concepts 

for situations where the traffic volumes were low 

enough that few Transportation Systems Management 

Operations (TSMO) strategies were required for a 

successful result. The fourth case study reworks one of 

the first three cases, but at moderately higher traffic 

volumes. This fourth case study illustrates how TSMO 

strategies can make a Complete Street design feasible 

and cost-effective under slightly higher volume 

conditions that might have otherwise precluded its 

further consideration by the agency.

Additional Complete Street and Road Diet case 

studies (without the emphasis on PBPD and TSMO) 

can be found in the following documents:

• Road Diet Case Studies (FHWA-SA-15-052) 

describes two dozen case studies of Road Diets 

in the United States. Additional information about 

Road Diets can be found at the FHWA Office of 

Safety Road Diets website at http://safety.fhwa.

dot.gov/road_diets.

• The Minnesota DOT research report, “Complete 

Streets from Policy to Project, The Planning and 

Implementation of Complete Streets at Multiple 

Scales,” has an appendix with several Complete 

Street case studies. It can be found at: http://

www.dot.state.mn.us/research/TS/2013/201330.

pdf

• Additional case studies can be found at the 

following FHWA websites:

• Livability Initiative http://www.fhwa.dot.gov/

livability/case_studies

• What is CSS? http://contextsensitivesolutions.

org/content/topics/what_is_css/changingsociety-communities/complete-streets/

Chapter 5 Case Studies

Source: Kittelson & Associates, Inc.
U.S. Department of Transportation | Federal Highway Administration

36

Chapter 5 Case Studies

CASE STUDY #1 – EDGEWATER 

DRIVE, ORLANDO, FLORIDA

A 1.5 mile long section of Edgewater Drive between 

Lakeview Street and W Par Street was examined for 

a Road Diet with the objective of bringing its design 

and operation into better conformity with the City’s 

College Park Neighborhood Horizon Plan, which had 

been recently approved by the local neighborhood 

association and accepted by the Orlando City Council 

(References 20 and 21). In this case, the existing road 

already had narrow 10-foot wide lanes, so the use of 

10-foot lanes in the Road Diet was not an issue.

Project Setting

The study section of Edgewater Drive extended 1.5 

miles from Lakeview Street to W Par Street. There are 

9 traffic signals on this stretch of Edgewater Drive. 

It carried approximately 20,000 ADT at the time of 

the study. The roadway serves as the College Park 

neighborhood’s main street, while accommodating 

some through traffic.

Performance-Based Practical Design

The four-lane configuration of Edgewater Drive with 

narrow lanes did not provide sufficient room for the 

wider sidewalks, bicycle lanes, streetscape and other 

neighborhood improvements called for in the recently 

adopted Neighborhood Horizon Plan. Preservation of 

existing curbside parking was a high priority for this 

stretch of Edgewater Drive due to the requirements 

of the existing land uses. A cost-effectiveness 

assessment of shifting the curbs one foot inwards 

to obtain wider sidewalks concluded that the costs 

exceeded the benefits to pedestrians of shifting the 

curbs. The design analysis determined that the most 

cost-effective Road Diet project would be to drop 

two travel lanes and use the cross-section gained for 

two bike lanes, a two-way, left-turn lane (TWLTL), and 

slightly wide parking lanes (see Figure 11).

Before and After Analysis

A before and after analysis of the Road Diet project 

concluded that:

• Traffic volumes dropped 12% on Edgewater Drive 

with the Road Diet.

• Traffic volumes on parallel and other 

neighborhood streets both increased and 

decreased (between -35% and + 31%). The average 

effect was a 4% decrease on all the parallel and 

other neighborhood streets studied.

• On-street parking utilization increased from 29% 

utilization to 41% utilization with the Road Diet.

• Pedestrian and bicycle volumes increased by 6% 

to 25% on Edgewater Drive. Bicycle and pedestrian 

volumes crossing Edgewater Drive (East-West) 

increased by 50% to 60%.

• The proportion of traffic traveling at over 35 mph 

on Edgewater Drive, which had been 10% on the 

middle section of the project, decreased to 9% 

with the Road Diet. The decreases in high speed 

traffic were greater at the northern and southern 

ends of the project.

• Crash rates (per million vehicle miles) were 

reduced 34%, injury rates were reduced 68% with 

the Road Diet.
37

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Chapter 5 Case Studies

Figure 11. Photos. Edgewater Drive, Orlando – Before and After Road Diet Complete Street Design.

(Source: Reference 22)

Road Before Road After

Figure 12. Diagrams. Edgewater Drive Road Diet Configuration
U.S. Department of Transportation | Federal Highway Administration

38

Chapter 5 Case Studies

CASE STUDY #2 – CORDOVA 

STREET, PASADENA, CALIFORNIA

A half-mile long section of Cordova Street between 

Lake and Hill Avenues was examined for a Road Diet. 

The project objectives were to: lower speeds, improve 

pedestrian safety, install bicycle lanes and improve 

pavement conditions. A four-lane, undivided street 

with no parking was converted to a two-lane street 

with a two-way, left-turn lane, bike lanes, and on-street 

parking (see Figure 13).

Project Setting

Cordova Street is located in a multi-family and 

commercial area of the City of Pasadena. It carries 

approximately 11,000 vehicles a day. The project 

section is one-half mile long.

Performance-Based Practical Design

The City’s objectives for the Road Diet project were to: 

install bicycle lanes (implementing the City’s bicycle 

system objectives), lower traffic speeds, and improve 

pedestrian safety.

The preservation of on-street parking was a high 

priority for the city given the needs of the adjacent 

land uses. Thus, on-street parking was retained in the 

Road Diet.

An early assessment determined that shifting the curb 

lines inward to increase the buffer space between 

motor vehicle traffic and pedestrians would greatly 

increase the costs and have marginal benefits to 

pedestrian safety. Consequently the curb lines were 

left in place.

The conversion of four through lanes to two lanes, a 

two-way, left-turn lane, and bike lanes was identified 

as a design solution that achieved the City’s objective 

of installing bicycle lanes, while potentially improving 

pedestrian safety by potentially reducing auto speeds 

on the street.

The selected design reduces the number of through 

lanes from four to two, adds bicycle lanes and a 

two-way, left-turn lane (see Figure 14). The existing 

travel lane widths of 11 feet per lane were retained in 

the Road Diet. The two-way, left-turn became leftturn pockets at the intersections. The parking lanes 

are replaced with crosshatching within 40 feet of the 

intersection.

Before and After Analysis

The City of Pasadena found that the Cordova Street 

Road Diet (Reference 23):

• Improved bicycle level of the street without 

adversely affecting pedestrian and motor vehicle 

levels of service.

• Caused a slight reduction in total collisions and 

injuries.

• Reduced traffic speeds on the street.
39

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Chapter 5 Case Studies

Figure 13. Diagrams. Cordova Street, Pasadena – Before and After Road Diet.

(Source: Reference 23)

Figure 14. Diagrams. Cordova Street Road Diet Configuration

(Source: Reference 24)
U.S. Department of Transportation | Federal Highway Administration

40

Chapter 5 Case Studies

CASE STUDY #3 – INGERSOLL 

AVENUE, DES MOINES, IOWA

A two-mile long section of Ingersoll Avenue between 

Polk Boulevard and Martin Luther King Parkway was 

examined for a Road Diet (see Figure 15). The City’s 

objective was to reduce traffic speeds, improve 

pedestrian and bicycle access, and add landscaping.

Project Setting

The study section of Ingersoll Avenue extended two 

miles from Polk Blvd. to MLK Parkway. It carried 

between 11,000 and 17,000 vehicles a day at the time 

of the study. 

Performance-Based Practical Design

The objectives of the Road Diet project were 

to reduce traffic speeds and increase safety for 

motorized and non-motorized modes on the street. 

The preservation of on-street parking was a high 

priority for the city given the needs of the adjacent 

land uses. Thus on-street parking was retained in 

the Road Diet. An early assessment determined that 

shifting the curb lines inward to increase the buffer 

space between motor vehicle traffic and pedestrians 

would greatly increase project costs and have 

marginal benefits to pedestrian safety. Consequently 

the curb lines were left in place.

The conversion of four through lanes to two lanes, a 

two-way, left-turn lane, and bike lanes was identified 

as a design solution that achieved the City’s objective 

of installing bicycle lanes, while improving overall 

safety for the street. The selected design reduces 

the number of through lanes from four to two, adds 

bicycle lanes and a two-way, left-turn lane (see Figure 

15). The two-way, left-turn lane became a left-turn 

pocket at the intersections. The parking lanes were 

replaced with right-turn lanes at the intersections.

Before and After Analysis

A simple before and after assessment of the Road 

Diet project found (Reference 23): 

• A 30-percent reduction in crashes. (Reference 10)

• A five-percent increase in lunch period traffic.

Figure 15. Diagrams. Ingersoll Avenue, Des Moines – Before and After Road Diet.

(Source: Reference 23)
41

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Chapter 5 Case Studies

CASE STUDY #4 – EMPLOYING 

TSMO TO EXPAND APPLICATION 

OF COMPLETE STREETS

The three case studies already described did not 

require the application of significant TSMO strategies 

to enhance the feasibility of their Complete Street 

designs. The traffic volumes and speeds were low 

enough that the design objectives could be achieved 

without employing significant TSMO measures.

To demonstrate how TSMO might support a Complete 

Street design, Case Study #3, Ingersoll Avenue, in Des 

Moines, Iowa, will be re-worked to assume a starting 

condition with moderately higher traffic volumes and 

speeds.

Traffic Operations Analysis

In this hypothetical extension of the Ingersoll 

Avenue example, the volumes are high enough that 

the agency needed to perform a traffic operations 

analysis to identify which TSMO measures might need 

to be employed to ensure that the Complete Street 

design would not sacrifice the agency’s mobility 

goals for the street. A number of tools could be used 

to evaluate traffic operations of the modified street, 

but the Highway Capacity Manual (HCM) is most 

common. The methodology of this peer-reviewed 

publication is the underlying methodology of many 

deterministic software tools. An HCM analysis could 

be performed at each signalized intersection and 

other critical unsignalized intersections and major 

driveways under the modified street condition, 

following the procedures as described in the relevant 

chapters of that reference. HCM analysis uses peakhour turning movements at each intersection and 

driveway to be evaluated. Existing signal-timing 

parameters would be another useful input; however, 

HCM supplied default values could be employed for 

the preliminary engineering analysis. The agency can 

later use the HCM analysis to determine the desired 

field settings for the signals when the Complete 

Street design is in place.

Identification of Operations Problems, 

Development of TSMO Solutions

If the HCM analysis determines that one or more 

intersection (or major driveway) movements might 

have operational problems (defined as LOS “F” 

delay, or excessive queues interfering with traffic, 

transit, bike, and pedestrian operations and safety 

on the street), then various TSMO solutions might be 

considered to support the Complete Street design.

• For through traffic operational problems, the 

signal timing might be examined and optimized 

to reduce delays and queuing. Signals might be 

coordinated to reduce through traffic queuing.

• For turn movement traffic operational problems, 

various TSMO mitigations might be considered.

• Optimize the signal timing to reduce turn 

pocket queue overflows.

• Consider removing curb parking on the 

approach to the intersection to provide an 

extra turn lane.

• Consider implementing Active Transportation 

and Demand Management (ATDM) features, 

like dynamic turn lanes, where left or right 

turns are allowed from the through lane as 

well as from the dedicated turn lane. This 

requires special signing, and signal control 

software to implement. There must be 

sufficient receiving lanes in the cross street 

for this option.

• If traffic operations problems threaten 

expeditious transit service on the street, the 

signal timing might be examined and optimized. 

A transit signal priority (TSP) system might be 

implemented. More-sophisticated versions of 

TSP may include transit vehicle identification and 

detection systems.

• If high traffic speeds are a concern for the 

Complete Street design, then the signal 

coordination might be re-examined to develop 

timing plans that favor lower through speeds.
U.S. Department of Transportation | Federal Highway Administration

42

Chapter 6 Summary and Conclusions
43

Operations in Performance-Based Practical Design: A Primer on Complete Streets

Chapter 6 Summary and Conclusions

This primer has highlighted how Performance-Based 

Practical Design (PBPD) supported by Transportation 

System Management and Operations (TSMO) 

strategies can advance Complete Street projects. 

It points out several references on design concepts 

for Complete Streets and methods for assessing the 

mobility and safety tradeoffs of different Complete 

Street design options.

PBPD considerations resulted in significant efficiencies 

for the Complete Street projects by ruling out early 

on design options that involved expensive shifting of 

curbs and gutters to achieve minor improvements in 

the achievements of the pedestrian safety objectives 

of the Complete Streets. Complete Streets preserved 

the existing curb lines and were able to achieve the 

majority of their safety and mobility objectives. 

Although not explicitly addressed in the primer, 

success with Complete Streets and Road Diets is also 

affected by institutional considerations and policy 

considerations. 

The following guides should be consulted for more 

information on these considerations and how TSMO 

strategies can support those policies:

• FHWA, “Road Diet Informational Guide”

• FHWA, “Incorporating On-Road Bicycle Networks 

into Resurfacing Projects”

• FHWA, “Separated Bike Lane Planning and Design 

Guide”

• The NACTO “Urban Street Design Guide” 

• FHWA Guide: “The Role of Transportation Systems 

Management & Operations in Supporting Livability 

and Sustainability: A Primer on Livability and 

Sustainability Considerations”

Chapter 6 Summary and Conclusions

Source: Kittelson & Associates, Inc.

45

Operations in Performance-Based Practical Design: A Primer on Complete Streets

References

REFERENCES

1. Public Roads, FHWA Street Design: Part 1—Complete Streets, by Robin Smith, Sharlene Reed, and Shana 

Baker, Publication Number: FHWA-HRT-10-005, Vol. 74, No. 1, July/August 2010.

2. FHWA, “Welcome to Business Process Frameworks for Transportation Operations”,

http://www.ops.fhwa.dot.gov/tsmoframeworktool/index.htm , accessed April 6, 2016.

3. Smart Growth America, http://www.smartgrowthamerica.org/complete-streets/complete-streetsfundamentals/complete-streets-faq, accessed February 27, 2016.

4. Urban Street Design Guide. National Association of City Transportation Officials.

5. FHWA. “Performance Based Planning and Programming Guidebook”, FHWA HEP 13-041, September 2013, 

http://www.fhwa.dot.gov/planning/performance_based_planning/pbpp_guidebook/.

6. 23CFR Part 625 – Design Standards for Highways; 625.3 Application; (f) Exceptions.

7. “Mitigating Strategies for Design Exceptions;”

http://safety.fhwa.dot.gov/geometric/pubs/mitigationstrategies/; July 2007.

8. Federal Register. May 5, 2016. https://federalregister.gov/a/2016-10299

9. FHWA. “Advancing Metropolitan Planning for Operations: The Building Blocks of a Model Transportation 

Plan Incorporating Operations – A Desk Reference”; FHWA-HOP-10-027; April 2010. http://www.ops.fhwa.

dot.gov/publications/fhwahop10027/fhwahop10027.pdf.

10. FHWA. “Advancing Metropolitan Planning for Operations: An Objectives-Driven, Performance-Based 

Approach – A Guidebook.”; FHWA-HOP-10-026; February 2010. http://www.ops.fhwa.dot.gov/publications/

fhwahop10026/.

11. FHWA. “Separated Bike Lane Planning and Design Guide”; FHWA-HEP-15-025; May 2015. http://www.fhwa.

dot.gov/environment/bicycle_pedestrian/publications/separated_bikelane_pdg/.

12. FHWA. “Designing for Transportation Management and Operations: A Primer,” FHWA HOP-13-013, available 

at National Operations Center of Excellence: http://www.transportationops.org/publications/designingtransportation-management-and-operations-primer-0.

13. AASHTO. Transportation Systems Management and Operations (TSMO), available at

http://www.aashtoTSMOguidance.org/.

14. TRB. 2010 Highway Capacity Manual, 2010.

15. AASHTO. Highway Safety Manual. 2010.

16. Sando, T., and R. Moses, Operational and Safety Impacts of Restriping Inside Lanes of Urban Multilane 

Curbed Roadways to 11 Feet or Less to Create Wider Outside Curb Lanes for Bicyclists – BDK82 977-01. 

Florida Department of Transportation. Tallahassee, FL. 2011.

17. Potts, I.B., et al. NCHRP Project 3-72: Lane Widths, Channelized Right Turns, and Right-turn Deceleration 

Lanes in Urban and Suburban Areas. Final Report. TRB. Washington, DC. 2006.
U.S. Department of Transportation | Federal Highway Administration

46

References

18. TRB. Highway Capacity Manual, 6th Edition. Publication Expected 2016.

19. FHWA. “Evaluation of Lane Reduction “Road Diet” Measures on Crashes” (FHWA-HRT-10-053, HRDS06/06-10(1M)E).

20. FHWA. Context Sensitive Solutions, Edgewater Driver Before and After Re-Striping Results. 

http://contextsensitivesolutions.org/content/case_studies/edgewater-drive/, accessed January 13, 2016.”

21. City of Orlando Transportation Planning Bureau, “Edgewater Drive Before and After Re-Striping Results”, 

November 1, 2002. Available at the FHWA Context Sensitive Solutions website.

22. FHWA. Center for Accelerating Innovation, Road Diets (Roadway Reconfiguration),

https://www.fhwa.dot.gov/innovation/everydaycounts/edc-3/roaddiets.cfm.

23. Road Diet Case Studies (FHWA-SA-15-052), available at:

http://safety.fhwa.dot.gov/road_diets/case_studies/, Accessed January 13, 2016.

24. City of Pasadena. “Road Diet FAQS”, http://cityofpasadena.net/Transportation/Road_Diet_FAQs/, accessed 

January 13, 2016.

25. Des Moines Area Metropolitan Transportation Organization. “On Street Bikeway Feasibility Study,” August 

2014, available at: http://dmampo.org/2014/11/18/on-street-bikeway-feasibility-study/.

Office of Operations

1200 New Jersey Avenue SE

Washington, DC 20590

Office of Operations Web Site

www.ops.fhwa.dot.gov

September 2016

FHWA-HOP-16-059