MAG proposes four-lane divided Pima Road, recommends signals and roundabout to address growth and safety

Maricopa Association of Governments (MAG) project manager Tim Stroh recommended a four‑lane divided arterial with a shared‑use path and sidewalks for the 4.1‑mile Pima Road corridor from Los Piedras to Cave Creek Road, telling the Scottsdale Transportation Commission the proposal aims to accommodate anticipated residential growth and improve safety.

“We are proposing a 4‑lane divided road with a shared use path and trail on the east side of the road and a sidewalk on the west,” Tim Stroh said. MAG’s report estimates about 4,000 acres of undeveloped state land in the corridor and projects roughly 5,000 homes could be built there, driving the need for corridor improvements and funding programming as Proposition 400 arterial lifecycle funds near the end of their availability.

The study evaluated cross‑section and intersection alternatives and recommended continuing the existing pattern south of the corridor — a four‑lane arterial with median, two lanes in each direction, bike lanes and multimodal facilities. At intersections, MAG recommended retaining existing signals at Lone Mountain Road and Westland Road; adding a signal at Stagecoach Pass; and building a multi‑lane roundabout at Cave Creek Road, where the roundabout concept outperformed a signal in 2035 and 2050 level‑of‑service models. Public feedback collected at two meetings favored signals at Lone Mountain (92% support) and Westland (87% support) and narrowly favored a roundabout at Cave Creek over a signal (47% vs. 53% for signal, per MAG’s outreach data).

The study flagged safety as a central concern: investigators reported more than 70 crashes in five years on the corridor, with 57% occurring between Stagecoach Pass and Cave Creek Road and one traffic fatality near Cave Creek and Pima. Stroh said one objective of the preferred design is to reduce travel speeds where the roadway currently transitions from 50 mph down to 35 mph and where lighting is limited.

Commissioners pressed study authors on safety tradeoffs between signals and roundabouts and on whether the analysis prioritized level‑of‑service (traffic flow) over crash severity. Vice Chair Wilcoxon and Commissioner Marmon cautioned that adding signals can increase certain types of severe crashes and that expanding capacity can in some cases increase speeds, potentially offsetting safety gains from geometric improvements. MAG consultant Carrie Coxon said the study compared crash types and severity and used benefit–cost metrics rather than a single LOS‑only metric; she acknowledged the project team did not perform a corridor‑wide LOS safety run separate from the operations modeling.

Staff and consultants clarified several implementation points raised by commissioners: MAG said state land in the corridor will be sold at auction and that development will be governed by zoning established before or during sale; David Rutkowski of the consultant team said auction outcomes are driven by zoning and highest bidder processes and that developers will generally be required to construct half‑street frontage improvements when they build. The team estimated the corridor build, including right‑of‑way and intersection work, at about $88,700,000; for the northern Segment 4 they broke out approximately $10,400,000 to the town of Carefree and $5,800,000 to the city of Scottsdale for their portions.

Next steps identified by MAG include finalizing recommendations with Scottsdale and Carefree staff, convening an Arterial Lifecycle Program working group, and advancing design funding and phasing discussions. Stroh said the team will incorporate stakeholder feedback as it refines designs and cost estimates.

Commissioners asked staff to bring greater emphasis on safety in subsequent design phases and to quantify tradeoffs between operational efficiency and crash risk in future materials. MAG and city staff said they would carry those requests into project design and funding discussions.