Since July 1, at least 18 people have died in traffic wrecks on a roughly 50-mile stretch of Route 160 between I-15 and Pahrump. But new housing construction and the resulting congestion have made the five-mile stretch directly southwest of Las Vegas the real danger zone.

Nevada Highway Patrol Trooper Kevin Honea describes the speed reduction -- to be accompanied by a full-court press of enforcement efforts -- as the first of several safety measures officials hope to implement.

Plans are underway to widen the road to eight lanes as far west as Decatur, starting this spring. The state Department of Transportation then hopes to widen as far west as Rainbow beginning next fall, with a bridge over the railroad crossing there.

In the meantime, NDOT has recommended installing rumble strips, and larger stop signs on intersecting streets -- the latter a call to which Clark County has already ”stepped up,” according to NDOT spokesman Bob McKenzie.

In the meantime, “We’ve come to a consensus on how to at least put a Band-Aid on it until everything is fixed,” Trooper Honea said last week. “If people are willing to abide by the (new) speed limit, I think it’ll make a considerable difference.”

Chad Dornsife, formerly of the National Motorists Association and now head of the Oregon-based Best Highway Safety Practices Institute, disagrees.

As a recipient of federal highway funds, Nevada has agreed to abide by the procedures laid out in the Manual of Uniform Traffic Control Devices when it comes time to make traffic engineering changes -- including the adjustment of speed limits -- Dornsife argues.

“Lowering the limit on Route 160 wasn’t done based on any engineering study. The director (Nevada Dept. of Transportation Director Jeffrey Fontaine) did it, they claim he has the authority. What you have here is government turning a section of road into a speed trap without dealing with the underlying safety issues. ...

“The proper procedure is you look at the accidents, you go back and look to see what’s causing them,” Dornsife insists. “You need to do a review of each accident. ...

“Lowering speed limits has never been shown to help,” Dornsife insists. “Studies show that lowering the speed limit doesn’t affect overall speeds when drivers perceive it’s safe to go faster. ... All it does is increases the number of traffic stops. Well, the California Highway Patrol has lost six officers in traffic stops in the past five months.” (Upon questioning, Mr. Dornsife clarifies that two of those officers were shot and three were hit by passing cars; one was killed in a pursuit.)

“They’re not safe. You improve safety by doing safety audits, an engineering audit. Changing speed limits and increasing the number of tickets issued has never reduced fatalities. And in Nevada you have no recourse.”

Nevada courts do not provide an independent hearing where drivers can challenge the legality of such arbitrary speed limit designations, Dornsife says, because “These courts are funded off traffic fines. ... It’s a vicious cycle where they feel they have to justify writing more tickets to fund the schools and the courts themselves.”

Because there are fewer accidents when traffic flows freely, the federally mandated MUTCD advises posting speed limits within 5 mph of the speed at which the 85th percentile of traffic is found to be traveling, Dornsife explains. (Of course, to determine that speed, you have to do a speed study.)

The new 45 mph limit “is 20 miles per hour below” the 85th percentile, Dornsife estimates. “It’s posted below the zero percentile. Where they’ll be writing tickets is not where the accidents have been occurring, but where the traffic has found it safe to go faster. ... They’ll ticket drivers that are otherwise driving safely. That’s not solving the real hazards.”

Dornsife says he called engineers at the Las Vegas office of the state DOT, and reached Kent Sears. “He claims (the MUTCD) is not a legal standard, it’s only a guideline. No, it’s a statutory requirement, the director can’t ignore it. I could go examine the accident sites, look for a solution from the toolbox of engineering remedies. I know how to reduce accidents in curves, passing zone incidents, at intersections. And I know none of these things has been done.”

How does Dornsife know that?

“I kept asking him ‘Where’s the study?' He keeps telling me, ‘It’s from the director’s office; he has the authority.’ So I can’t get the study; I suspect there is none.”

I tried to call NDOT engineer Kent Sears. My calls were instead returned by NDOT Public Information Officer Bob McKenzie, who then got Fred Droes, the department’s chief traffic safety engineer, on the line from Carson City.

“The manual that Chad quotes, the Manual of Uniform Traffic Control Devices, gives a pretty broad description of what an engineering study is,” Fred Droes replied. “It talks about a comprehensive study and evaluation of pertinent information, it talks about things you should consider -- road characteristics, shoulder conditions, grades, traffic volume, and one of the big ones is reported crashes for a 12-month periods.

“We’ve looked at those things. We did not have the opportunity to go out there and collect vehicle speeds, we’re pretty sure what we’re going to find, which is people traveling at a pretty high rate of speed except where it’s congested conditions. We lowered the speed based on the conditions, the volume and the crash experience. That was all included in documentation that was given to the director’s office.”

And does Mr. Droes consider that document to be the federally required engineering report?

“I certainly do, even though it’s very brief, two or three pages.”

NDOT faxed me engineer Droes’ March 2 memorandum to the director, which is really one page, with a second page set aside for signatures. It cites the accident rate and the increased traffic volumes, measured just west of the intersection with Decatur Boulevard. But it neither includes nor references any recent study of actual measured speeds, nor any analysis of whether high speed (or anything else) contributed to any of the individual, recent accidents.

What about Dornsife’s contention that speed rarely causes these accidents -- that for the most part cars travel fast where rational drivers have determined it’s safe to do so, while accidents occur in congested areas, sometimes due to impatient drivers who may only become more impatient when speed limits are lowered?

“We’re not just lowering the speed limit without doing anything else,” engineer Droes replies. “NHP is out there doing some intensive enforcement, trying to change driver behavior. ... We’re going to continue to study the problem, and we’re going to do more. But in there we did document 500 crashes, six of them fatal. And when you get that, you’re justified in lowering the speed limit.

“It may not be in the format or to the extent that Chad Dornsife would like to see, but we’re satisfied that we looked at that corridor and we had sufficient grounds to lower the speed limit.”

In the real political world, of course, it would have taken a mighty brave engineer to refuse to do anything while spending more weeks “conducting studies.”

But I did spot an interesting line in director Fontaine’s March 2 “Certification of Establishment of Speed Limits,” lowering the limit on SR 160 to 45 mph. (Yep, the same day he got Frederick Droes’ recommendation. And here you thought bureaucrats moved slow.)

The NDOT director writes, “Based on the factors in the Manual on Uniform Traffic Control Devices for setting speed limits and speed studies conducted by the Nevada Department of Transportation, a recommendation for speed limits on the Nevada State Highway System Routes has been made by the Chief Traffic Engineer as shown in the attached memorandum ...”

Funny thing, though. Fred Droes told me on March 9 “We did not have the opportunity to go out there and collect vehicle speeds.”

Why would the director cite “speed studies conducted by the Nevada Department of Transportation” as a basis for the speed limit change, if none were done? Could it be because Chad Dornsife has a point, and a considerably more “comprehensive” engineering study really is required?