As a lengthy and detailed transportation study, the information presented on this site includes both current and archived data. Some of this data may no longer be accurate or applicable to the current status of the proposed freeway study. While we have tried to separate current from archive information, ADOT is sincerely committed to conducting this study openly and fairly, so we have maintained many years worth of documents, presentations and other information as part of this site to help provide a comprehensive reference for all members of the community until the formal environmental documents are released for public review and comment. If you have questions about the current-day accuracy of a document or want to inquire about the latest developments, we are always happy to provide personal assistance.

These changes have been made due to the declining revenues that Maricopa County has been faced with since 2007. Maricopa County’s half-cent sales tax for transportation projects, approved through Proposition 400 in 2004, is the major funding source for the Regional Transportation Plan and provides more than half of the revenue. These declines are the first ever in the history of the transportation sales tax since first being approved in 1985.  In addition, funding for regional projects from ADOT and the federal government have declined and are expected to continue declining.

In response, MAG began to study methods to reduce freeway project costs. Additionally, during the South Mountain Freeway study the public expressed concern about the number of proposed residential and business acquisitions and about some of the potential impacts of the proposed freeway. Acknowledging these community concerns and addressing declining revenues, strategies were examined to reduce potential impacts including project costs and needed right-of-way. For the South Mountain Freeway Study, this analysis resulted in two key changes:

• reduce the proposed freeway to eight lanes (from the previous 10-lane concept), thereby reducing the right-of-way needed;
• shift the Western Section alignment between Lower Buckeye Road and I-10 to connect at 59th Avenue (rather than 55th Avenue).

In October 2009, MAG’s Regional Council voted to approve the revised regional plan which included these changes. If you would like more information regarding the Regional Transportation Plan, please visit the MAG Web site at www.mag.maricopa.gov.

In November 2004, Maricopa County voters approved a 20-year extension of a half-cent sales tax until 2026 to fund a comprehensive package of transportation improvements as part of a Regional Transportation Plan. Funding for the plan, which includes $9 billion in regional freeway improvements in Maricopa County, became effective January 1, 2006.

Responding to federal transportation planning requirements, the RTP is being extended through 2031 by the Maricopa Association of Governments (MAG) to maintain a 20-year planning horizon. As a result, a fifth phase has been added to the RTP, covering the period from 2026 through 2031. Consistent with federal planning guidelines, funding for transportation projects is based on revenue sources that are considered to be reasonably available for the planning period. This assumes that for planning purposes funding sources with a long history of providing funding in the past will continue into the future.

In fall 2009, due to declining sales tax revenues and decreases in other transportation revenue sources to fund improvements, MAG recommended that some future projects be deferred to Phase V of the plan. As part of the planning process, project costs and funding levels are continuously monitored, and the RTP is periodically updated to take advantage of cost savings or changes in the transportation revenue outlook. This can result in the acceleration of projects that were formerly deferred. For more information about RTP projects deferred to Phase V in the MAG tentative scenario, please visit the MAG Web site.

The planning stage establishes the general location (alignment) and basic characteristics (number of lanes, type of traffic interchange, etc.) of a roadway. Accompanying this are environmental studies (noise, traffic volume, etc.), identification and evaluation of alternatives, general cost estimates, coordination with public and private partners and the determination of feasibility to move to the design phase.

The design of a roadway involves several phases of detailed engineering and technical review and interim levels of approval. The final design of the roadway is represented in plans and specifications that construction contractors use to prepare construction bids.

Road construction for projects is based on detailed plans and specifications provided to the contractor following the approved design. ADOT continually looks for ways to improve the construction process for maximum efficiency and minimal community impact. Once built, a roadway may be improved over time as a result of future studies.

ADOT continually plans for enhancements to the roadway once it is built and in use for maximum efficiency and safety. Various studies identify these enhancements and may influence additional planning, design and construction.

Funding for the South Mountain Freeway was approved by voters in November 2004 with the passage of Proposition 400, which continued an existing half-cent sales tax through 2025 for improvements identified in the Regional Transportation Plan (RTP).

The Arizona Department of Transportation is charged with implementing the highway component of the Regional Transportation Plan which includes $13.2 million in new freeways, freeway improvements and maintenance.