Revision of Thirteen Controlling Criteria for Design and Documentation of Design Exceptions, 27187-27191 [2016-10299]

Agencies

• Federal Highway Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 81, Number 87 (Thursday, May 5, 2016)]
[Notices]
[Pages 27187-27191]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-10299]



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DEPARTMENT OF TRANSPORTATION

Federal Highway Administration

[FHWA Docket No. FHWA-2015-0020]


Revision of Thirteen Controlling Criteria for Design and 
Documentation of Design Exceptions

AGENCY: Federal Highway Administration (FHWA), Department of 
Transportation (DOT).

ACTION: Notice.

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SUMMARY: The geometric design standards for projects on the National 
Highway System (NHS) are incorporated by reference in FHWA regulations 
in 23 CFR 625 and apply regardless of funding source. These design 
standards are comprehensive in nature, covering a multitude of design 
characteristics, while allowing flexibility in application. Exceptions 
may be approved on a project basis for designs that do not conform to 
the minimum or limiting criteria set forth in the standards, policies, 
and standard specifications.
    The FHWA is updating its 1985 policy regarding controlling criteria 
for design, applicable to projects on the NHS, to reduce the number of 
controlling criteria from 13 to 10, and to apply only 2 of those 
criteria to low speed roadways. The FHWA is also issuing guidance to 
clarify when design exceptions are needed and the documentation that is 
expected to support such requests. The FHWA's guidance memorandum, 
which is available in the docket (FHWA-2015-0020), transmits this 
policy to FHWA field offices.

FOR FURTHER INFORMATION CONTACT: For questions, contact Elizabeth 
Hilton, Geometric Design Engineer, FHWA Office of Program 
Administration, telephone 512-536-5970, or via email at 
Elizabeth.Hilton@dot.gov. For legal questions, please contact Robert 
Black, Office of the Chief Counsel, telephone 202-366-1359, or via 
email at Robert.Black@dot.gov, Federal Highway Administration, 1200 New 
Jersey Avenue SE., Washington, DC 20590. Business hours for the FHWA 
are from 8:00 a.m. to 4:30 p.m., e.t., Monday through Friday, except 
Federal holidays.

SUPPLEMENTARY INFORMATION:

Electronic Access and Filing

    This document, the request for comments notice, and all comments 
received may be viewed online through the Federal eRulemaking portal 
at: https://www.regulations.gov. The docket identification number is 
FHWA-2015-0020. The Web site is available 24 hours each day, 365 days 
each year. Anyone can search the electronic form of all comments in any 
of our dockets by the name of the individual submitting the comment (or 
signing the comment, if submitted on behalf of an association, 
business, or labor union). You may review DOT's complete Privacy Act 
Statement in the Federal Register published on April 11, 2000 (65 FR 
19477), or you may visit https://DocketsInfo.dot.gov.

Request for Comments

    On October 7, 2015, FHWA published a Notice with Request for 
Comments (80 FR 60732) soliciting public comments on proposed revisions 
to the 13 controlling criteria for the design and the documentation 
that is expected to support requests for design exceptions. When used 
in this notice, the term ``design exception'' refers to documentation 
prepared for projects on the NHS when a controlling criterion is not 
met, and that must be approved in accordance with 23 CFR 625.3(f), by 
FHWA or on behalf of FHWA if a State Transportation Agency (STA) has 
assumed this responsibility through a Stewardship and Oversight 
agreement.

Background

    As codified in 23 CFR 625.3 and 625.4, the geometric design 
standards for projects on the NHS are A Policy on Geometric Design of 
Highways and Streets (2011) and A Policy on Design Standards Interstate 
System (2005), published by the American Association of State Highway 
and Transportation Officials (AASHTO). As codified in 23 CFR 625.3(f), 
exceptions may be approved on a project basis for designs that do not 
conform to the minimum or limiting criteria set forth in the standards, 
policies, and standard specifications adopted in 23 CFR 625. In 1985, 
FHWA designated 13 criteria as controlling criteria, requiring design 
exceptions when any of these 13 criteria were not met.
    The FHWA proposed to eliminate 3 criteria, rename others, and focus 
the application of most criteria on high-speed roadways (i.e., design 
speed >=50 mph). The 10 controlling criteria proposed for design of 
projects on the NHS were: Design Speed, Lane Width, Shoulder Width, 
Horizontal Curve Radius, Superelevation, Stopping Sight Distance, 
Maximum Grade, Cross Slope, Vertical Clearance, and Design Loading 
Structural Capacity. The FHWA proposed that all 10 controlling criteria 
would apply to high-speed roadways on the NHS, and that only two, 
Design Speed and Design Loading Structural Capacity, would apply on 
low-speed roadways (i.e., design speed <50 mph) on the NHS.

Purpose of the Notice

    The purpose of this notice is to publish final designation of the 
controlling criteria for design of projects on the NHS and how they 
will be applied in various contexts, and describe the design 
documentation needed to support requests for design exceptions. While 
all of the criteria contained in the adopted standards are important 
design considerations, they do not all affect the safety and operations 
of a roadway to the same degree, and therefore do not require the same 
level of administrative control. The FHWA encourages agencies to 
document design decisions to demonstrate compliance with accepted 
engineering principles and the reasons for the decision. Deviations 
from criteria contained in the standards for projects on the NHS which 
are not considered to be controlling criteria should be documented by 
the STA in accordance with State laws, regulations, directives, and 
safety standards. States can determine their own level of documentation 
depending on State laws and risk management practices.

Designation of Controlling Criteria

    Based on the comments received in response to FHWA's proposal, 
combined with FHWA's own experience and the findings of National 
Cooperative Highway Research Program (NCHRP) Report 783 ``Evaluation of 
the 13 Controlling Criteria for Geometric Design'' (2014), the 10 
controlling criteria for design are:
     Design Speed;
     Lane Width;
     Shoulder Width;
     Horizontal Curve Radius;
     Superelevation Rate;
     Stopping Sight Distance (SSD);
     Maximum Grade;
     Cross Slope;
     Vertical Clearance; and
     Design Loading Structural Capacity.
    All 10 controlling criteria apply to high-speed (i.e., Interstate 
highways, other freeways, and roadways with design speed >=50 mph) 
roadways on the NHS. The SSD applies to horizontal alignments and 
vertical alignments except for sag vertical curves. On low-speed 
roadways (i.e., non-freeways with design speed <50 mph) on the NHS, 
only the following two controlling criteria apply:
     Design Loading Structural Capacity; and
     Design Speed.

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Design Documentation

    Design exceptions, subject to approval by FHWA, or on behalf of 
FHWA if an STA has assumed the responsibility through a Stewardship and 
Oversight agreement, are required for projects on the NHS only when the 
controlling criteria are not met. The FHWA expects documentation of 
design exceptions to describe all of the following:
     Specific design criteria that will not be met.
     Existing roadway characteristics.
     Alternatives considered.
     Comparison of the safety and operational performance of 
the roadway and other impacts such as right-of-way, community, 
environmental, cost, and usability by all modes of transportation.
     Proposed mitigation measures.
     Compatibility with adjacent sections of roadway.
    Design Speed and Design Loading Structural Capacity are fundamental 
criteria in the design of a project. Exceptions to these criteria 
should be extremely rare and FHWA expects the documentation to provide 
the following additional information:
     Design Speed exceptions:
    [cir] Length of section with reduced design speed compared to 
overall length of project.
    [cir] Measures used in transitions to adjacent sections with higher 
or lower design or operating speeds.
     Design Loading Structural Capacity exceptions:
    [cir] Verification of safe load-carrying capacity (load rating) for 
all State unrestricted legal loads or routine permit loads and, in the 
case of bridges and tunnels on the Interstate, all Federal legal loads.
    The FHWA encourages agencies to document all design decisions to 
demonstrate compliance with accepted engineering principles and the 
reasons for the decision. The approval of deviations from applicable 
design criteria are to be handled as follows:
    1. The project is located on a NHS roadway and controlling criteria 
are not met: In accordance with 23 CFR 625.3(f), design exceptions are 
required and FHWA is the approving authority, or exceptions may be 
approved on behalf of FHWA if an STA has assumed the responsibility 
through a Stewardship and Oversight agreement, with documentation as 
stated above.
    2. The project is located on a NHS roadway and non-controlling 
criteria are not met: STA is the approving authority for design 
deviations,\1\ in accordance with State laws, regulations, directives, 
and safety standards. States can determine their own level of 
documentation depending on State laws and risk management practices.
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    \1\ The term ``deviation,'' when used in this document, refers 
to any departure from design criteria that does not require FHWA 
approval because either the criteria is non-controlling or the 
facility is not on the NHS. States often refer to these instances as 
design deviations or variances.
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    3. The project is located on a non-NHS roadway and the State design 
criteria are not met on a Federal-aid project: STA is the approving 
authority for design deviations, in accordance with State laws, 
regulations, directives, and safety standards. States can determine 
their own level of documentation depending on their State laws and risk 
management practices.

Analysis of Comments

    The FHWA received comments from 2,327 individuals and organizations 
on the proposed changes to the controlling criteria. Of these, 2,167 
were individual form-letter comments delivered to the docket by 
Transportation for America. Of the remaining, 87 were from individuals, 
23 from STAs, 22 from other public entities, 18 from private 
organizations, 5 from industry associations, 4 from private firms, and 
1 from an elected official. The comments are summarized below.

General Comments

    Many commenters referred to the proposed changes as a rulemaking. 
The controlling criteria are not established by Federal regulation, 
instead they are a matter of policy. The proposed changes are not a 
rulemaking as they will not modify the CFR and will not impose binding 
requirements that have the force and effect of law. The proposal was 
published as a notice in the Federal Register as a way to invite public 
comment on the proposed policy changes.

Controlling Criteria

    All but 7 of the 2,327 commenters support revisions to the 
controlling criteria. Some supporters suggested changes which were 
considered by FHWA, as shown below.
    1. Over 2,100 commenters asked FHWA to replace the term ``design 
speed'' with ``target speed'' for low-speed NHS roadways so that 
roadway design elements could be selected to meet community needs and 
provide safety for all modes of transportation.
    Response: No changes were made. The proposed changes, combined with 
recent clarification by FHWA about design speeds and posted speeds 
(available at https://www.fhwa.dot.gov/design/standards/151007.cfm), 
allow agencies the flexibility to design based on target speed while 
remaining consistent with the terminology used in the adopted AASHTO 
standards. The FHWA forwarded this comment to the AASHTO Technical 
Committee on Geometric Design for its consideration.
    2. The National Association of City Transportation Officials asked 
FHWA to clarify that there is no minimum design speed.
    Response: No changes were made. Minimum design speeds are included 
in the adopted standards for the NHS and design exceptions are required 
if a lower design speed is selected. The FHWA forwarded this comment to 
the AASHTO Technical Committee on Geometric Design for its 
consideration.
    3. Three STAs recommended retaining vertical clearance as a 
controlling criterion on low-speed roadways to ensure that insufficient 
vertical clearance on a minor roadway would not result in damage to an 
overpassing high-speed roadway, such as an Interstate highway or other 
freeway.
    Response: No changes were made. The FHWA agrees that vertical 
clearance is an important criterion and that insufficient clearance on 
one roadway may negatively impact the overpassing roadway. However, 
States are already managing the scenario described if the low-speed 
roadway is not on the NHS. Under this revised policy, States would 
continue to manage the risks associated with insufficient vertical 
clearance for all low-speed roadways (non-freeway), including those on 
the NHS.
    4. The Oregon DOT and a few individuals thought that 50 mph was too 
high for the threshold between high- and low-speed roadways, citing 
concerns about urban expressways and that freight vehicles need wider 
lanes.
    Response: The speed threshold remains unchanged. The intent was to 
capture all freeways in the high-speed category. For clarification, 
FHWA revised the definition of high-speed roadway for the purposes of 
this policy to include all Interstate highways, other freeways, and 
roadways with design speed greater than or equal to 50 mph.
    5. The Wisconsin DOT recommended using a posted speed of 40 mph to 
define the threshold, stating that a design speed of 50 mph is too high 
given the likelihood of pedestrian fatalities at that speed.
    Response: No changes were made. The proposed threshold was chosen 
for consistency with AASHTO policy documents adopted through regulation 
at 23 CFR 625.4. The policy allows maximum design flexibility for roads

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with a design speed less than 50 mph which can be applied in ways that 
improve pedestrian safety.
    6. The Indiana DOT asked FHWA to clarify that the superelevation 
criterion is for rate only, and that transition length and distribution 
are not subject to a design exception.
    Response: The FHWA concurs and clarified the term in the 
controlling criteria list.
    7. The Indiana DOT asked FHWA to clarify the application of SSD to 
vertical and horizontal curves.
    Response: Clarification was added. The SSD applies to a variety of 
situations and is well described in A Policy on Geometric Design of 
Highways and Streets (2011). As noted in NCHRP Report 783, SSD has 
little impact on the safety and operations at sag vertical curves under 
daytime conditions when the driver can see beyond the sag vertical 
curve, or at night, when vehicle taillights and headlights make another 
vehicle on the road ahead visible in or beyond a sag vertical curve. 
Therefore, the application of SSD at sag vertical curves is excluded 
from the controlling criterion.
    8. The Minnesota DOT suggested eliminating design speed as a 
controlling criterion on low-speed roadways.
    Response: No changes were made. Design speed must be retained 
because it is a fundamental criterion in the design of the project and 
because it sets the threshold for application of the controlling 
criteria. If, for example, design speed was not a controlling criterion 
for low-speed roadways, practitioners could simply select a lower 
design speed to avoid the controlling criteria requirements for high-
speed roadways.
    9. The Georgia DOT and two others commented that lateral offset to 
obstruction should be retained as a controlling criterion.
    Response: No changes were made. Lateral offset is most relevant to 
urban and suburban roadways to ensure that mirrors or other 
appurtenances of heavy vehicles do not strike roadway objects and 
passengers in parked cars are able to open their doors. While these are 
important considerations, they do not rise to the same level of effect 
as other controlling criteria proposed to be retained and do not 
require the same level of administrative control.
    10. The Wisconsin DOT recommended retaining lane width, 
superelevation, stopping sight distance, and cross slope as controlling 
criteria for low-speed roadways, and adding a new controlling criterion 
for critical length of grade.
    Response: No changes were made. The FHWA finds that removing these 
controlling criteria from application in low-speed environments is 
supported by research and provides additional flexibility to better 
accommodate all modes of transportation. No new controlling criteria 
are proposed at this time.
    11. The Wisconsin DOT commented that bridge width is not redundant 
if lane and shoulder widths are dropped from the controlling criteria 
list in the low-speed environment, which may result in choke points 
that are expensive to correct. They also commented that vertical and 
horizontal clearances can influence structural ratings; that stopping 
sight distances at intersections can be critical; and that the 
combination of flat grades and cross slopes is problematic.
    Response: No changes were made. While these criteria are important, 
the risk of deviations can be handled by STAs in accordance with their 
risk management practices.
    12. The Wisconsin DOT asked why clear zone was not included in the 
updated controlling criteria.
    Response: No changes were made. The Roadside Design Guide was not 
adopted as a standard under 23 CFR 625. Instead it serves as guidance 
with regard to roadside safety. Therefore, adoption of values in the 
Roadside Design Guide as controlling criteria would not be appropriate.
    13. A few commenters asked FHWA to adopt additional controlling 
criteria to require the provision of bicycle and/or pedestrian 
facilities on roadways.
    Response: No changes were made. Such a policy would require a 
regulatory change which is beyond the scope of this controlling 
criteria policy.
    Several commenters supporting changes to the 1985 policy requested 
clarifying guidance in the final notice, as follows:
    1. Clarify requirements for non-NHS Federal-aid projects.
    Response: This policy change does not modify existing regulations. 
Per 23 CFR 625.3(a)(2), ``Federal-aid projects not on the NHS are to be 
designed, constructed, operated, and maintained in accordance with 
State laws, regulations, directives, safety standards, design 
standards, and construction standards.'' The FHWA reiterated in this 
notice that the controlling criteria apply only to the NHS.
    2. Limit application on the NHS to new construction and 
reconstruction projects, and/or clarify that the proposed modifications 
will not reduce current State flexibility regarding projects that are 
not new construction or reconstruction.
    Response: This policy change does not modify existing regulations. 
It is not limited to new construction and reconstruction projects on 
the NHS. Title 23 CFR 625.4(a)(3) states that ``resurfacing, 
restoration, and rehabilitation (RRR) projects on NHS highways other 
than freeways'' may utilize the design criteria established by the 
State and approved by FHWA. The regulations do not allow the adoption 
of RRR criteria for NHS freeways. The FHWA Division Administrator is 
allowed to determine the applicability of the roadway geometric design 
standards to traffic engineering, safety, and preventive maintenance 
projects which include very minor or no roadway work under 23 CFR 
625.3(e).
    3. One commenter asked FHWA to clarify that States can be more 
restrictive than Federal guidance proposed here, while other commenters 
asked FHWA to encourage State DOTs to apply the same logic to non-NHS 
facilities.
    Response: States may adopt policies that are more restrictive than 
the revised FHWA policy published here. The FHWA encourages agencies to 
work together with stakeholders to develop context sensitive solutions 
that enhance communities and provide multiple transportation options to 
connect people to work, school, and other critical destinations. The 
FHWA notes that the Fixing America's Surface Transportation (FAST) Act 
of 2015 includes new provisions encouraging design flexibility. The 
FHWA also issued a memorandum in 2013 expressing support for taking a 
flexible approach to bicycle and pedestrian facility design. The 
memorandum is available at  https://www.fhwa.dot.gov/environment/bicycle_pedestrian/guidance/design_flexibility.cfm.
    4. A few commenters expressed concern that FHWA is abandoning 
safety on low speed roadways, or that some designers will view non-
controlling criteria as less important.
    Response: The FHWA developed this proposal, based on the findings 
in NCHRP Report 783 and FHWA's experience, to give agencies the 
flexibility to balance the safety and operations of all modes of 
transportation, while reducing administrative requirements where they 
do not clearly result in improved safety and operations. The FHWA 
encourages agencies to document all design decisions to demonstrate 
compliance with accepted engineering principles and the reasons for the 
decision.

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Deviations from criteria contained in the standards for projects on the 
NHS which are not considered to be controlling criteria should be 
documented by the STA in accordance with State laws, regulations, 
directives, and safety standards. States can determine their own level 
of documentation depending on State laws and risk management practices. 
Agencies are responsible for the training and development of their 
employees.
    5. Clarify that design exceptions are not required for non-
controlling criteria.
    Response: Clarifying language was added to the Design Documentation 
section that stated design exceptions are not required for non-
controlling criteria.
    6. For low-speed roadways, clarify that elements dependent on 
design speed that are substandard do not require a design exception. 
For example, design speed is 40 mph (and does not require a design 
exception), but the minimum curve radius provided meets 35 mph (no 
design exception is required).
    Response: For non-freeways, the controlling criteria categories are 
based on design speed, which puts the project in one of two groups: 
High-speed or low-speed. Within each category, design exceptions are 
only required when the controlling criteria are not met. In the example 
provided, a non-freeway with a 40 mph design speed in accordance with 
the AASHTO criteria would be classified as low-speed. Design exceptions 
would only be required if the design speed or design loading structural 
capacity criteria were not met. No changes were made to the text of the 
policy.
    7. The Wisconsin DOT asked what will be allowed for the National 
Network (Federally designated long truck routes per 23 CFR 658) if lane 
and shoulder widths are not important for safety and operations.
    Response: All of the criteria contained in the adopted standards 
are important design considerations. They do not all affect the safety 
and operations of a roadway to the same degree, and therefore should 
not require the same level of administrative control. Changes to the 
controlling criteria policy do not modify the regulations contained in 
23 CFR 658.
    8. The Wisconsin DOT asked what consideration was given to oversize 
and overweight vehicles.
    Response: As noted in Chapter 2 of the A Policy on Geometric Design 
of Highways and Streets, the designer should consider the largest 
design vehicle that is likely to use that facility with considerable 
frequency or a design vehicle with special characteristics appropriate 
to a particular location in determining the design of such critical 
features as radii at intersections and radii of turning roadways. 
Designers are responsible for proper consideration of oversize and 
overweight vehicles and all other aspects of the project context.
    9. The Southern Environmental Law Center asked FHWA to clarify 
whether rural roads with a design speed of less than 50 mph remain 
subject to the 10 remaining design criteria.
    Response: No changes were made. The application of the controlling 
criteria is the same regardless of urban or rural designation.
    Seven private citizens oppose changes to the controlling criteria 
policy. Five of the seven who oppose the changes believe the proposed 
flexibility will divert scarce Federal gasoline and road taxes to non-
highway purposes.
    No changes were made as a result of these comments. The design 
standards for the NHS and design exception process apply regardless of 
project funding. Revising the controlling criteria gives communities 
the ability to develop a transportation system that best serves their 
needs, but does not change existing laws or regulations pertaining to 
project expenses eligible for Federal reimbursement.
    Several comments were received that do not pertain directly to the 
controlling criteria policy. The Southern Environmental Law Center 
recommends changes to the design speeds shown in the AASHTO Green Book 
to reflect a range instead of a single minimum number, as currently 
shown for three of the categories (rural freeway, urban freeway, and 
urban collector). The criterion for urban collectors should vary 
according to the different types of terrain. Likewise, the low end of 
the design speed range for urban collectors in mountainous terrain 
should be the same 20 mph minimum used for collectors in rural 
mountainous terrain. Finally, the definition of the term ``urban'' 
should be revised to include areas of low density sprawl that now 
surround most cities.
    This comment is outside the scope of this notice. The FHWA 
forwarded this comment to the AASHTO Technical Committee on Geometric 
Design for its consideration.
    Comments pertaining to the need for bicycle and pedestrian 
accommodation on bridges; appraisal ratings contained in the National 
Bridge Inspection Standards; the definition of pavement reconstruction; 
design loading for military vehicles; and the methods for determining 
posted speeds were also received.
    These comments are outside the scope of this notice but were 
forwarded to the appropriate program office within FHWA for 
consideration.

Design Exception Documentation

    Sixteen commenters provided comments on the proposed documentation 
expected in support of requests for design exceptions. Fourteen STAs, 
AASHTO, and the Chicago DOT all commented that the level of 
documentation proposed for design exceptions would be burdensome and 
would result in less flexibility than currently exists for roadways 
with a design speed greater than 50 mph. They also believe that such a 
requirement is at odds with FHWA's current emphasis on Performance 
Based Practical Design (PBPD). Instead of providing an inclusive list 
of items to be addressed in design documentation, they recommend that 
any list be more suggestive in nature. Agencies asked FHWA to remove 
the requirement for quantitative operational and safety analysis, and 
expressed concern that references to the environment and community 
would add too much specificity.
    The PBPD is a design-up approach to address the purpose and need of 
a project and emphasizes the need to document design decisions made 
under this approach. Therefore, FHWA sees no inconsistency between the 
design documentation proposed here and the PBPD approach. In response 
to the concerns expressed, FHWA modified the language regarding the 
safety and operational analysis such that it does not require a 
quantitative analysis in all cases. The level of analysis should be 
commensurate with the complexity of the project. The FHWA notes 
however, that the FAST Act adds the Highway Safety Manual (HSM) to the 
list of publications FHWA shall consider when developing design 
criteria for the NHS. The FHWA strongly encourages agencies to utilize 
the HSM procedures to the maximum extent applicable. The FHWA retained 
references to the environment and community because design exceptions 
to address these concerns are not uncommon, and therefore need to be a 
part of any documentation.

Conclusion

    The overwhelming support for changes to the controlling criteria 
indicate that the changes will support agency and community efforts to 
develop transportation projects that support community goals and are 
appropriate to the project context. The provisions included here for 
design documentation will result in more

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consistent evaluation of exceptions to the adopted design standards 
when controlling criteria are not met on NHS highways.

    Authority: 23 U.S.C. 109 and 315; 23 CFR 1.32 and 625; 49 CFR 
1.85.

    Issued on: April 22, 2016.
Gregory G. Nadeau,
Administrator, Federal Highway Administration.
[FR Doc. 2016-10299 Filed 5-4-16; 8:45 am]
 BILLING CODE 4910-22-P