Driving in America: Musings from Arizona’s Interstate 17

By NMA Arizona Member Rod Harris

For 15 years, I have commuted at least once a week between the greater Phoenix area and Flagstaff, AZ, roughly 130 miles each way, on Interstate 17. In my experience, the average speed was more or less the speed limit, when and where that limit is 75 mph.

Of course, there were lane hogs in the left of two lanes doing 70 or less. And rogues doing 85+. In my opinion, the left-lane hogs caused more of a problem, as they would sometimes pace big rigs that were in the right lane and create a backup of dozens of cars behind them. That sort of driving resulted in frustration and risky behavior such as snap lane-changes, passing on the right, etc.

One of my “favorite” experiences was tailgating a semi in the passing lane doing 27 in a 75 mph zone while passing another semi doing 25 in the right lane!

Then there are areas when the speed limit drops to 65, such as descending into the Camp Verde valley from both the north and south. One can argue that this is reasonable, as both descents involve fairly steep downhill curves.

Credit: Bernard Gagnon

On the other hand, for vehicles with any degree of sporty handling, the routes are not an issue unless one were to blow a tire or swerve to avoid an obstacle. I would guesstimate the average speed in normal times to be closer to 70 mph in these areas.

However, in my opinion, the decrease in speed limit (from 75 to 65) is introduced a mile or two before they are needed in both directions. And others seem to agree. In my observation, unless police are observed, the speed decreases don’t really happen until the point where the 85th percentile rule kicks in.

The same is common at construction zones, where the speed limit is reduced from 75 to 65 to 55 (even 45) starting two, three, or even four miles before any construction zone. I have not noticed this in other states in which I drive.

Again, in my opinion, the restoration of the 75 mph limit happens miles after it would be “reasonable and prudent,” i.e., the descent angle and amount of curvature have decreased substantially.  So, in these areas, the average speed again approaches 75 mph, which I would judge to be the 85th percentile speed.

Equivalent milder grades and curves elsewhere on I-17 remain posted at 75 mph, unlike the above areas.

I have noticed that there are maybe eight or so common speed trap areas in each direction in the 130-mile route that I have driven probably 1000+ times.  Several of them are where the limit is an arbitrary 65, as opposed to what should be 75 in accordance with the 85th percentile standard.  So, I am speed-conscious when approaching those spots to make sure I am not inadvertently over the posted limit.  But those with less (or no) experience on the route are often caught.

Enter the Covid-19 Lockdowns
Traffic in Phoenix and Flagstaff dropped dramatically as untold numbers were laid off from their jobs or transitioned to work-from-home. Traffic patterns changed dramatically.

Credit: TheDoctorWho

First, traffic volume dropped significantly, both within the cities and between them on I-17.  So did enforcement.  Sightings of highway patrol vehicles became scarce.  Accident sightings were far fewer. Those highway patrol vehicles I did spot virtually never were using radar. (Yes, I have a detector.)  I guess that the police were reluctant to engage people who might have the virus, absent a highly volatile situation.

Pullovers were almost non-existent, absent an accident or disabled vehicle. An occasional tactic by the H.P. of parking an empty marked patrol vehicle at common speed-trap locations became the norm. So the Waze app would announce, “Caution!  Speed trap ahead.”  But there would be no radar or laser detected.

As drivers woke to this reality, the average speed on I-17 increased significantly. I would guesstimate that in 75mph zones, it went to 80, maybe 82. And 90 was far from rare. In 65 mph zones, I would say 75 became the norm. I would guess that this began around the beginning of spring, which was also close to the pandemic’s start.

Then the era of protests and some riots began, more or less in the same time frame as the Covid-19 shutdowns began to evolve.  Immediately, the Friday afternoon and Saturday traffic from Phoenix toward Flagstaff went up by an order of magnitude.  And Sunday traffic Southbound did the same. Traffic jams became the norm.

At the same time, average real-estate prices up North began to escalate, as did the level of sales. My theory is twofold:

  1. People began to be afraid to fly due to Covid-19.  So they decided to buy a vacation spot to which they could drive only a couple of hours north to the mountains.
  2. Although not a huge factor in the Phoenix area, some peaceful protests devolved into violence. For example, Scottsdale Fashion Square was looted and was shown widely on the local and national news.  Other such events occurred around town, but not nearly to the scale as in Portland or Seattle. Yet Phoenix is the 5th largest city in the country, and the potential still exists.

In addition to those who chose not to fly for vacation, a faction was added that wanted a “safe space” to which they could escape if Phoenix were to become a riot-center.

At the beginning of summer, the I-17 traffic was close to normal on weekdays, in my estimation.  It became heavier than before the COVID crisis going north on Fridays and Saturdays and going south on Sundays. Police sightings became more common but not yet “normal” in my experience.

I would say that the higher average speeds from spring are now the “new normal,” other than in traffic jams, of course. Police pullovers have resumed but still seem far less common than in my previous 15 years of the commute on I-17.

A side story:  Every year, brush fires are distressingly frequent on I-17 during the Spring-Summer period. They are particularly common at or near the Sunset Point rest-stop, around Mile Marker 252. This year they seemed to be much more frequent than in previous years.

The shoulders of I-17 have miles of surface brush growth 12-18″ tall that historically has never been mowed or managed. Arizona tends to be hot and dry absent a productive monsoon season. The 2020 Monsoon was a complete bust, and much of the state has a drought.

So, the combination of cigarette butts being tossed criminally out vehicle windows, as well as pull-overs for stalls, flat tires, overheated engines, etc., trigger brush fires. (The average catalytic converter is quite capable of igniting dry brush.)

All of this leads up to my final question:

With the significant increase in average speed on I-17 that continues now, plus the dramatic increase in weekend traffic, has there been any increase in accidents and/or injuries/fatalities?  So far, I have not seen or heard any coverage of this question in the media.

Rod Harris is an Arizona Member of the National Motorists Association. If you have a driver’s musing from your neck of the woods, send us an email at [email protected].

Editor’s Note: The opinions expressed in this article are those of the author.

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