Key points:

• Arizona may become first state with no maximum speed limits on some highways

• Rep. Nick Kupper proposes 80 mph speed limit on rural roads, with option for no limit

• Higher rural speed limits could cut travel time on Arizona’s highways significantly

PHOENIX — Arizona could become the only state in the nation without a maximum speed limits on some of its highways.

Rep. Nick Kupper is proposing that speed limits on rural roads be at least 80 miles per hour in rural areas, five miles faster than the highest limits now on any Arizona highway.

But his HB 2059 would allow the director of the state Department of Transportation to deregulate entirely rural stretches of highway so that there would be no posted limit at all during daylight hours for non-commercial traffic.

And to prove his argument that removing speed limits is not unsafe, the legislation actually would mandate a pilot project, designating the entire stretch of Interstate 8 between Casa Grande and Yuma as a “derestricted speed zone” for at least a year to see whether it affected crash rates.

That, however, would be during daylight hours, and only for noncommercial vehicles. Trucks, buses and trailers would be limited to 80. And that would be the top speed for everyone at night.

Then, as Kupper sees it, ADOT would use that information to decide whether, first, to keep that designation in place on I-8 and, later, to expand deregulate speeds on other interstate highways in non-urbanized areas, defined as any stretch where there are 50,000 or fewer residents.

That could mean deregulating speed limits along large expanses of Interstates 10, 17, 19 and 40, along with a segment of I-15 that runs through the northwest corner of Arizona.

It also would make Arizona the only state in the nation with no posted speed limit on some of its highways.

“I fully appreciate the fact that, naturally, your first inclination is: that’s craziness, you’re going to kill people,” Kupper said.

“However, the data proves otherwise,” he continued. “And I want to do this pilot program to prove that we can actually do this and save lives.”

Kupper cited research from Montana. He said that higher limits resulted in more motorists driving similar speed limits, actually resulting in fewer accidents.

That is backed by a report by the Montana Department of Transportation which, looking at other studies, said that crash severity “may increase because of variances in speed and not because of  higher speeds,” though that study also included not just divided access highways but also two-land roads.

“It’s kind of an interesting psychological phenomenon where when you don’t have a set speed limit, people tend to coalesce around a certain speed,” Kupper said.

Yes, he said, overall speeds went up about 5 miles per hour.

“However, what was really interesting, was that the fastest person and the slowest person tended to be closer in speed to each other than when you have a set speed limit,” Kupper said. “And when you have less of a variance, you have fewer accidents and fewer fatalities.”

There even is some local evidence to back up that contention.

In 2023, ADOT boosted the speed limit on a stretch of I-17 from 55 mph to 65, saying that the higher limit “can result in more drivers traveling closer to the same speed, which enhances safety.”

And ADOT made the same comment last week when it raised the speed limit on a four-lane stretch of State Route 24 in southeast Maricopa County from 45 to 55 miles an hour.

Anyway, Kupper said, if police aren’t focused on speed they can pay more attention to other issues, like using a phone while driving or not wearing a seat belt, “things that will get you killed.”

Kupper said he understands that there will be some who will insist that higher speeds will lead to more dead motorists.

“Now, they don’t have any data to prove me wrong,” he said.

“Naturally, it feels wrong,” he said. “And people go by feelings. I get it.”

But the Insurance Institute of Highway Safety says it actually does have the data to contradict what Kupper is claiming.

“Research has found that higher speed limits are associated with more crash fatalities,” said Joseph Young, the organization’s director of media relations.

“A study of 25 years of speed limit increases across the country found that raising the state speed limit by 5 mph results in about an 8% increase in fatality rates on those roads with the highest speed limits like interstates,” he said. Overall, Young said, over that 25 years about 37,000 deaths could be attributed to a speed limit increase.

Kupper said, however, none of that should affect his proposal to scrap the current 75 mph speed limits on rural interstates.

“People are going 10 to 15 over already,” he said.

In fact, he said, that’s why he chose Interstate 8 as his one-year test area.

“They’re traveling faster than that right now 85 to 90 as it is,” Kupper said, with long straight stretches and few entrances and exits. “The data that I’ve been able to pull shows that, per vehicle mile traveled, it is the safest interstate we have.”

Anyway, he said, it’s not like once the limits are lifted that’s the end of the discussion.

“If the data comes back and the ADOT director says, ‘It’s more dangerous,’ we don’t do it any more, it’s over,” Kupper said.

“It gives them the authority after a year to continue on,” he said. “Or, I guess, if we at the Legislature decide to do something different with it, we could.”

But Kupper said he doubts that lawmakers would unilaterally rescind the deregulated designation on that stretch of road.

What higher rural speed limits would mean is cutting travel time.

Consider that trip to San Diego on Interstate 8, the road that would be the test area.

It’s about 150 miles between the edges of the urban areas of Casa Grande and Yuma. At 75 miles an hour — assuming no bathroom or burger breaks — that’s about two hours and 20 minutes.

Bump the speed up to 95 takes about 30 minutes off of that.

And it’s not like his legislation would mean motorists could do what they want on rural interstates — even if the ADOT director agreed that change is merited in certain areas.

His bill still would require people to drive at a speed that is “reasonable and prudent.” And that is specifically defined for those derestricted stretches as speed that is excessive given road and weather conditions, traffic volume, visibility, the vehicle’s mechanical condition — and “a driver’s reaction time.”

But Kupper said that last factor doesn’t mean highway patrol officers will be administering tests to motorists they have stopped to gauge their reaction time. Instead, he said, it means someone following too closely given the speed they were going.

“Let’s say you’re going 85 miles per hour and you’re 20 feet behind the car in front of you.” he said. “That is not reasonable,” Kupper said. `I think everyone could assume that. It’s not going to give you the reaction time to put on the brake if something happens.”

Young said questioned whether it’s safe to simply declare that anything that “reasonable and prudent” is legal.

“It may prove challenging for officers to enforce,” he said.

And Young said if Arizona does boost speed rural interstate speed limits — whether just to 80 or deregulate entirely — the state should be sure there’s a clear plan in place to enforce those limits, and not just in the highways.

“Research has shown that higher speed limits can have a spillover effect on nearby roads where there was no intention to change the limit,” he said.