Information from Marc F. Della Rocca, Community Relations Manager, Coconino County Public Works
Dear Ms. Krushinsky,
Last month, Gregory Nelson from Supervisor Matt Ryan’s office asked that I contact you regarding recent concerns over speeding and dust in Sherwood Forest Estates. I apologize for not being able to do so you sooner; however, it took more time than usual to research your questions and suggestions due to being sequestered away from the office and our team for COVID-19 social distancing. In any case, I thank you for your patience and hope that I can provide some information for you regarding these issues.
Speed + Dust = Springtime Issue #1
Not surprisingly, speeding and dust are the primary spring-season concerns of County residents who live on unpaved roads. I’m sure that you can imagine why…dry, windy conditions, coupled with a significant influx of second homeowners and visitors, dramatically increase seasonal dust in County neighborhoods each spring. The challenge of mitigating this dust and the speeding that causes it dust is compounded by several factors:
Law Enforcement is Key
First of these factors is that the only effective way to mitigate speeding is through law enforcement. As speeding is ultimately a safety issue, citations from the Coconino County Sheriff’s Office (CCSO) deputies provide a costly reminder to those who would otherwise speed through County neighborhoods.
Limitations of Signage
County signage is important. Without CCSO enforcement, however, signs are essentially just reminders to follow a given speed limit, the effectiveness of which relies on the honor system of motorists and riders. Irrespective of this fact, we still receive regular requests from residents to increase the number of speed limit signs (or add other types of speed and dust mitigation signs) on County roads where speeding occurs.
To this end, it is equally important to understand that County sign placement is not an arbitrary practice but, instead, a data-driven process that is governed by federal Manual of Uniform Traffic Control Devices (MUTCD) guidelines. The need for/number of a given sign, along with its design, content, reflectivity and placement, is determined by MUTCD criteria (a.k.a. “warrants”) that are used to consider a variety of factors such as a road’s Average Daily Trip (ADT) count, line-of-sight considerations and accident data.
This protocol, of course, includes speed limit signs. FYI, I researched but could not find any MUTCD-approved specialty signs for dust control; if they do exist, however, then they also would be governed by this protocol.
Speed Limit Reductions
The same warrant criteria of signage also would apply to the process required to lower speed limits in the hopes of mitigating dust in Sherwood Forest Estates. Please note that only the County Engineer can change a given speed limit, and then only pursuant to a comprehensive traffic study that looks at a wide variety of empirical criteria as described above. Ironically, these studies can, in some cases, recommend that the speed limit on a given road be raised rather than lowered based on accident and ADT data.
Regarding speed limits, please note that, in Arizona, the speed limit for residential roads is set at 25 mph irrespective of whether (speed limit) signage is present. With this in mind, I researched the speeds and accident data within Sherwood Forest Subdivision. Please note that, throughout the entire Sherwood Forest subdivision, there have only been three (3) reported accidents since 2005: on Knighthood Lane (cause: animal / deer strike); on Long Bow Drive (cause: snow & ice) and in 2016 on Friar Tuck Trail in 2017 (cause: driver ran a stop sign into the adjacent ditch). With regards to driving speeds, please note that the 85th percentile speed (or the average speed that 85 percent of drivers are going) recorded during this traffic count did not exceed 27 miles per hour on any of these roads, which is well within acceptable tolerances.
Proliferation of Off-Road Vehicles
Of all challenges associated with speeding and fugitive dust, none comes close to the explosive popularity of Off-Road Vehicles (ORV’s) in County communities. Easy to operate and designed to go fast, ORV’s like Razors and Side-by-Sides have become “standard issue” equipment for both full- and part-time residents over the past few years. ORV’s generate an inordinate amount of dust, which is one reason that complaints about dust have increased so dramatically over the last few years compared to the time when a comparatively small number of Jeeps and dirt bikes were the only vehicles used for off-road travel.
Finally, it is important to understand that the County cannot afford to provide dust suppression on the more than 700 miles of dirt roads in its inventory. Even if this were possible, it is doubtful that it would be even marginally effective against the dust generated by ORV’s, which also cause significant wear and tear on the roads we maintain. Still, some residents do provide their own dust suppression by forming Special Maintenance Districts. Provided by Arizona statute (https://www.azleg.gov/
In closing, I would encourage you to continue contacting CCSO at 928-774-4523 to report speeding in your neighborhood as it is important to have an official record of all incidents. While maintaining that additional County signage and/or a speed limit change will do little to dissuade those would otherwise be inclined to speed on residential roads, you might still want to try placing a sign (“Slow Down”, etc.) on the private, roadside portion of your property to help in this effort. Please note that no sign or other object can be placed in County right-of-way without first securing an encroachment permit.
I hope that this information is of interest. Thanks for your time, and I hope that this email finds you well,
Marc F. Della Rocca
Community Relations Manager
Coconino County Public Works