Flagstaff transportation staff asked the Transportation Commission on Thursday to add speed humps to the city's traffic-calming toolbox, and commissioners signaled support for including the devices in the Residential Traffic Management Guide and for lowering the speed-thresholds needed to qualify a neighborhood for traffic calming.

The proposal, presented by Sydney Juve, Transportation Engineer Associate, would allow speed humps on local streets, permit speed cushions on minor collectors and commercial local roads to reduce emergency-response impacts, and recommend a minimum of two devices spaced roughly 250'600 feet apart with modification for long blocks. Juve said speed humps typically reduce speeds by 5 to 13 miles per hour, cost about $7,500 per hump, are 3'4 inches high and about 12'14 feet long in the direction of travel, and that the city's existing threshold requires 30 percent of vehicles to travel at least 5 mph over the limit to qualify for traffic calming.

The discussion followed public comment from several residents of the Lower Greenlaw neighborhood. Amy Byers, a Lower Greenlaw resident, told the commission her street carries "over 900 cars daily" and has no sidewalks, forcing pedestrians to share the roadway with speeding vehicles. "We're not asking for luxury, we're asking for basic safety," Byers said. Cliff Balderas and Thomas Byers, also Lower Greenlaw residents, urged temporary rubber humps, additional stop signs at specific intersections and other low-cost measures to make the neighborhood safer for children and elders.

Fire Chief Mark Gaylord said emergency response time is the department's primary concern when traffic-calming devices are added. "Traffic calming and anything that slows down the emergency response component for any reason I think is the concern that we always have," Gaylord said, while also noting the department has worked with staff to mitigate those concerns and was open to devices such as speed cushions that emergency vehicles can straddle.

Commission feedback generally supported Juve's recommendations: add speed humps to the Residential Traffic Management Guide, allow them on local streets, allow speed cushions on minor collectors, consider lowering the 30 percent threshold (staff showed that lowering to 15 percent would have added two candidate projects over the past five years and lowering to 10 percent would have added six), require a minimum of two devices, and further discuss funding and implementation details. Commissioners and staff also raised implementation issues including snow-plowing impacts, drainage on older streets, pavement and maintenance needs, and signage and marking to reduce liability and help plow operations.

No formal vote was taken. Staff said they will package the recommendations for the City Council, including options on funding (city-funded program, partial resident cost-share models used by other cities, or mixed approaches), and return with more refined thresholds, spacing guidance, and an internal review process that includes stormwater, fire and police input before final neighborhood-level outreach.

Residents and commissioners urged a cautious roll-out: pilot locations, coordination with public works on maintenance and signage, and further data on spacing for long blocks so humps do not simply shift speeding to the stretches between devices. Juve and staff said the commission's feedback would be incorporated for a future City Council presentation.