Attachment A - MAG Study.pdf

ATTACHMENT A

Management Committee
INFORMATION SUMMARY

AGENDA ITEM # 5H
DATE
Vln September 7, 2023

MARICOPA n,...,

ASSOCIATION of —_

GOVERNMENTS Update on the interstate 10: Deck Park Tunnel to
the Interstate 10/Interstate 17 Split Freeway
Corridor Planning Study
CONTACT
Bradlee Williams, Transportation Engineer, (602)
254-6300.

SUMMARY

Funding was identified for the Interstate 10 (I-10): Deck Park Tunnel to the I-10/Interstate
17 (I-17) Split Freeway Corridor Planning Study as part of the Fiscal Year (FY) 2022-2023
Biennial Unified Planning Work Program and Budget. This section of I-10, known as the
“Inner Loop,” was one of the last portions of the Federal Interstate Highway Program to
be built in Arizona. Now, 30 years later, this section is one of the most heavily congested

highways in the region.

MAG initiated the study in March 2022. In addition to the portion of I-10 between the
Deck Park Tunnel and the I-10/I-17 Split interchange, the study also includes portions of
State Route 51 (SR 51) and the I-10/Loop 202/SR 51 system interchange, known as the
“Mini Stack.” This section of I-10 provides critical regional connectivity, including access
to downtown Phoenix, Sky Harbor International Airport, regional entertainment districts,
and access to other freeways.

In addition to high levels of congestion, the corridor is also faced with unreliable travel
times — in part due to the large number of vehicle crashes occurring in the corridor.

Project Objectives:

To manage the study, a project team comprised of staff from the Arizona Department of
Transportation (ADOT), City of Phoenix, Federal Highway Administration (FHWA), Sky
Harbor International Airport, Federal Aviation Administration (FAA) and MAG was
formed. The study team has generated five objectives to be achieved by the
recommendations of this study, which are described below.

> Improve safety
In the six years from 2016 to 2021, there has been an average of more than five

crashes per day along this six-mile freeway corridor. Improving safety is a high
priority.

> Enhance traffic operations
As part of the study, bottleneck locations, queuing, and speed differential — the
difference in speeds found in different lanes — are being identified. Speed
differential creates weaving difficulties, incentives for queue jumping, and sudden
stops and starts. All of these together cause inefficient traffic operations and
increase the potential for crashes.

> Enhance access to and from downtown Phoenix and Sky Harbor Airport
Improvements to I-10 could affect street congestion levels, intersection operations,
and circulation within downtown Phoenix as well as the airport. Consideration is
being given to the impact of proposed improvements throughout the entirety of

the system.

> Protect the surrounding communities from negative impacts
The study team is identifying where there may be issues to the surrounding
communities. The intention is to include these issues in the evaluation to be sure
the needs of the communities are adequately considered as different improvement
strategies are evaluated and recommendations are proposed.

> Accommodate regional travel needs
This section of I-10 accommodates a lot of regional, statewide, and interstate

traffic.

Alternatives Being Evaluated:

Altogether, the study team is considering more than 100 ideas for improving this freeway
corridor. Alternatives range from physical improvements, such as the addition of lanes
or relocation of entry/exist ramps to reduce weaves, to operational improvements such
as improving communications or changing the use of specific lanes.

The study is scheduled to conclude its alternatives assessment late this year and to bring
its recommendations to MAG committees in the spring. The study’s final
recommendations will establish the framework for future improvements funded through
the extension of Proposition 400.

PUBLIC INPUT

The public engagement plan has begun. A public survey will be conducted in September
and October to receive comments on the key issues to be addressed in the study; an in-
person public meeting will be held in the winter of 2024 to present and receive
comments on the recommendations.

PROS & CONS

PROS: Improvements to I-10 between the Deck Park Tunnel and the I-10/I-17 Split
Interchange will enhance regional connectivity, improve travel time reliability, and
improve safety for motorists and non-motorists.

CONS: None.

TECHNICAL & POLICY IMPLICATIONS

TECHNICAL: The identification of alternative improvements is completed, and the
alternatives are currently being evaluated for their effectiveness.

POLICY: The study's final recommendations will establish the framework for future
improvements funded through the extension of Proposition 400.

ACTION NEEDED

Information and discussion.

PRIOR COMMITTEE ACTIONS

None.