Kingman staff outline transportation master plan, signal timing fixes and near-term options for Hualapai Mountain Road at Andy Devine

City of Kingman engineers presented the city’s Transportation Master Plan and intersection analyses to the Planning and Zoning Commission on June 11, saying long‑range projects remain prioritized while staff will pursue near‑term engineering work at the Hualapai Mountain Road and Andy Devine Avenue intersection.

The presentation matters because the intersection is at or near capacity during peak hours and staff said physical improvements — beyond signal retiming — will be required to ease congestion as growth increases traffic volumes.

Mike Grama, the city engineer, told the commission the Transportation Master Plan adopted by council in December 2023 is the city’s guide for transportation decisions and assumes a 2045 build‑out horizon. “This is a map that’s from our transportation master plan that was adopted by council in December 2023,” Grama said, and he described the plan’s functional classifications for local, collector and arterial streets and the set of prioritized projects included in the Capital Improvement Program (CIP).

Jack Plante, assistant public works director, focused on the Hualapai Mountain Road–Andy Devine intersection and recent traffic studies. Plante said the Transportation Master Plan used 2022 traffic data for modeling and that the Wallapai/Andy Devine intersection already showed “moderate congestion in 2022.” He added the city has performed counts, turning‑movement studies and multiple signal timing adjustments. “We’ve made multiple changes to that intersection through traffic analysis and timing adjustments,” Plante said, but he warned the intersection “is saturated” and that further physical improvements are needed.

Plante described two interim options the city is considering in the coming fiscal year: creating a slip lane using existing right of way behind nearby commercial properties to carry an eastbound movement on Andy Devine, or adding a dedicated right‑turn lane at the intersection. He said funds will be set aside starting the fiscal year that begins July 1 to pay for an engineering analysis and a low‑level design concept report.

The presentation placed flying projects such as the Flying Fortress Parkway (also referenced during discussion as the Rattlesnake Wash interchange) and Cayman Crossing in the CIP as longer‑term priorities. Grama and Plante said portions of those corridors will be built by developers (for example, Engel Homes is named as a primary builder for a segment of Kingman Crossing) while other segments lie outside city limits and would require coordination with Mohave County or ADOT. Plante noted the city’s portion of Flying Fortress Parkway would stop at Southern Avenue and that construction of the southern extension would require county action.

Plante also noted project ranking is sensitive to updated traffic counts and development patterns: the Slaughterhouse Canyon Road project was ranked 45 of 67 in the original TMP; Plante said that project had been estimated “at around 10,000,000” (amount units not specified in the presentation) and that newer traffic growth could raise its priority, though he said it was unlikely to jump to the top of the list. He emphasized that crossing BNSF railroad tracks at Slaughterhouse Canyon would complicate costs and permitting and likely require an overpass or underpass because BNSF “does not want at grade crossings.”

Commissioners asked about roundabouts, funding sources, developer obligations and signal‑timing strategies. Plante and Grama said roundabouts have been considered in some locations but often require large right of way and may not be appropriate where volumes or utilities constrain geometry. They described the city’s practice of adjusting signal phases by time‑of‑day plans (morning westbound favoring, evening eastbound favoring) and said those timing changes have helped but cannot fully resolve saturation without physical lane or geometry changes.

Staff next steps and direction from the meeting: staff will begin engineering analysis and prepare a design concept report for the Andy Devine–Hualapai intersection in the new fiscal year, evaluate the two interim geometric options described, and continue coordination with developers and Mohave County for connector roads identified in the TMP. No formal action or vote was taken; the item was information only.

Plante and Grama said the TMP remains the policy guide for future projects and that priorities may shift as updated traffic volumes and development submittals change forecasts. The commission asked staff to return with engineering options and cost estimates when available.