Saving Fuel: UPS Saves Fuel and Reduces Emissions the “Right” Way by Avoiding Left Turns
Abstract:
For more than a century, UPS has made efficient routing a top priority. Careful route planning is fundamental to the way UPS does business and essential for safe and timely deliveries.UPS achieves efficiencies through careful study of the methods used to deliver packages. UPS learned through time studies that avoiding left-hand turns saves time, conserves fuel, lowers emissions and increases safety. UPS managers used to plan routes by hand on maps while driving to destinations. They then experimented with the routes, eliminating left-hand turns to see if it led to increased efficiency. It worked. For the past several decades, UPS has designed routes in a series of loops with as few left-hand turns as possible.In the past few years, UPS rolled out technology that automates the process for minimizing left-hand turns. Today, UPS managers combine personal and historical experience with computer programs to design delivery routes.Since the deployment of this route planning technology in 2004, UPS has eliminated millions of miles off delivery routes, taking already-expedient routes and giving them razor edge efficiency.As a result, UPS:

Saved 10 million gallons of gas
Reduced CO2 emissions by 100,000 metric tons, equivalent to 5,300 passenger cars off the road for an entire year.

For more information, contact:

UPS Public Relations

404-828-7123

http://www.pressroom.ups.com/Fact+Sheets/ci.Saving+Fuel%3A+UPS+Saves+Fuel+and+Reduces+Emissions+the+%22Right%22+Way+by+Avoiding+Left+Turns.print

Tom Vanderbilt calls left turns “the bane of traffic engineers.” The diverging diamond interchange, he says, is one way to get around them.Roughly 10 million motor vehicle accidents are reported on U.S. roads every year. Regular drivers may not be surprised to hear that many of them involve cars making left turns. Some drivers go to great lengths just to avoid making a difficult left.Traffic engineers have figured out some alternatives to the standard, four-way intersection, including the Jersey jughandle and the Michigan left. But most still involve crossing directly in front of oncoming traffic.

In a piece for Slate, “Don’t Turn Left,” Tom Vanderbilt investigates another solution: the diverging diamond interchange. He tells NPR’s Tony Cox, “Engineers for decades have dreamed of basically eliminating left turns.
Interview Highlights

On why two rights are better than a left

“Especially on a busy, multi-lane road, you’re going to make a left turn … you have to navigate across several lanes of oncoming traffic — something that humans are a little bit bad at doing, judging the speed and distance of approaching vehicles — it’s sort of a stressful maneuver.”

On why dedicated left-turn lanes aren’t the answer

“This is when you have the green arrow that allows only you to make a left turn. This is better for the driver, but it’s worse for the intersection as a whole, because every time you give that special phase, you’re taking away from all the other motions in that intersection. So a left-turn phase is incredibly inefficient in the eyes of engineers.”
cafachiever/YouTube

Watch a diverging diamond interchange in action.

On how the diverging diamond works

“It’s one of the more innovative and experimental ideas out there… Imagine that you’re on a north-south arterial road … and you’re crossing over an interstate highway that runs east-west. So you’re going north and you want to go west, you need to make a left … In the diverging diamond, as you’re approaching the interstate, the two lanes of traffic basically criss-cross. As you go through the first traffic light, you’re asked to go across what you think is the normal flow of traffic. You sort of veer to the left, and if you’re going to head west on that intersection, you just go off on this ramp that’s specially dedicated only for left turns. If you want to continue straight, you continue going straight, then loop back through another set of criss-crosses, back into the right lane of traffic.”

On the chance you’ll be driving through one soon

“There’s only been about a half-dozen built to date, but there are many more either in the works or on the planning boards. There are about several dozen other innovative intersection treatments that are on people’s wish lists or in the stages of being drafted.”

Copyright © 2011 National Public Radio®. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.

TONY COX, host: Every year, roughly 10 million motor vehicle accidents are reported on the roads, and it may not be a surprise to regular drivers that many of them happen during a left turn. Traffic engineers have come up with alternatives to the standard four-way intersection, like the Jersey jughandle and the Michigan left and the more ubiquitous roundabout. Yet most still involve crossing directly in front of another oncoming vehicle. It is indeed a driving dilemma, but there may be hope. In a piece for slate.com, transportation columnist Tom Vanderbilt proposes a solution: the diverging diamond exchange. Oh, let me get that right. The diverging diamond interchange.

To give you an idea of what he’s talking about, we have a video of this design on our website. Go to npr.org and click on TALK OF THE NATION. You can see how it works for yourself. What’s your left-turn strategy? Do you even have one? 800-989-8255. That’s our phone number here. Our email address is talk@npr.org. And you can join the conversation at our website. Go to npr.org. Click on TALK OF THE NATION.

Tom Vanderbilt, joining us now from our bureau in New York. Tom, welcome to the program.

TOM VANDERBILT: Hi, Tony. Great to be here.

COX: I want to ask you this first. Why are left turns so tough to design in a safe and efficient manner?

VANDERBILT: Well, yeah. I mean, just to foreground this whole discussion, engineers, for decades, have dreamed of basically eliminating left turns. And this is something that we’ve heard. Famously, UPS has special routing software when they send their trucks out to try to have their drivers make as many right turns as possible. I mean, an ideal trip would be nothing but right turns.

And the question is why do two rights – why are two rights better than a left? And, I mean, it’s sort of intuitive to anyone who’s out there driving. You’re – especially on sort of a busy, multi-lane road. You’re going to make a left turn. Either you have to navigate across several lanes of oncoming traffic – something that humans are a little bit bad at doing, judging the speed and distance of approaching vehicles. It’s sort of a stressful maneuver.

Or they’ll turn to – they have sort of what’s called a dedicated, left-turn phase. This is when you have the green arrow that allows only you to make a left turn. This is sort of better for the driver, but it’s worse for the intersection as a whole, because every time you give that special phase, you’re taking away from all the other motions in that intersection. So a left turn phase is incredibly inefficient in the eyes of engineers.

COX: Oh, so it makes you have to just sit there and wait forever and ever and ever for the person to make a left turn. And if they’re texting or on the phone and don’t see it and don’t make the turn while the green light’s there, you have to wait for a whole another cycle to go through.

VANDERBILT: Exactly. Or several cycles. And then just to complicate things further, you know, by the time that left – that green left arrow turns yellow and then red, they even have to build in a few extra seconds, what’s called the clearance phase, to make sure every driver has gotten out of the middle of that intersection. The clearance phase has only gotten longer as drivers sort of seem to increasingly test those red lights. And so you have to wait for the intersection to clear, which is, again, adds time.

COX: So you have the idea, right? You have the idea for us?

VANDERBILT: Well – now this is, of course, is not my idea, and it only applies in certain situations. But it’s one of the more, let’s say, innovative and experimental ideas out there, and it’s basically called the diverging diamond interchange. And this is the sort of thing, it’s like – it’s a bit – trying to explain it in words is sort of like trying to describe to someone how to tie a complicated knot. I mean, it’s better sort of seen, but I’ll give it a go.

Imagine that you’re on sort of a north-south arterial road, like in a suburban environment, and you’re crossing over a highway, interstate highway, and you want to take – that runs east-west. So you’re going north. You want to go west. You need to take a left turn to get onto that intersection. In a normal sort of situation, you would go over the interstate and probably have a green arrow – wait for that green arrow to have to take a left turn across those lanes of traffic.

The diverging diamond, what it does, as your approach – as you go over the – excuse me. As you’re approaching the interstate, the two lanes of traffic basically crisscross. And as you go through the first traffic light, you basically are asked to go across what you think is a normal flow of traffic. You sort of veer to the left. And then if you’re going to head west on that intersection, you just go off on this ramp that’s specially dedicated only for left turns. If you want to continue straight, you continue going straight, then loop back through another set of crisscrosses back in the right lane of traffic. So I’m sure I’ve already confused (unintelligible) – I’ve confused myself.

COX: Well, you know, it is confusing to describe. I have seen it, so I understand what you’re talking about. And to look at it, you can see that it makes a certain amount of sense trying to describe it this way. We’ll probably drive our listeners crazy and you as well. But we’ll do the best we can to put the explanation of how this might work and where it already is in effect. But before we do that, let’s take a couple of phone calls. We’ve got Jim standing by from Jackson, Wyoming. Jim, welcome to TALK OF THE NATION.

JIM: Good afternoon. When I go to town, I plan my route, and I make nothing but right-hand turns. Right-hand turns on the way into town, attend to all my business, right-hand turns on the way out. I can’t believe how many people I see here in motor homes that will make a left-hand turn to get into a Shell station and then they have to make a left-hand turn to get back out of the Shell station.

COX: Well, Jim, what if you’re in a hurry? I mean, you’re taking all those rights. That slows you down, doesn’t it?

JIM: Well, I know, I mean, I’m taking rights. I plan my trip accordingly, so that I make my stops where I’m only making right-hand turns.

COX: Alrighty, and that works for you. How long have you been doing that?

JIM: A long time.

COX: A long time and it works for you.

JIM: It definitely does.

COX: Thank you very much for the call. Let’s go to Ken in St. Louis, Missouri. Ken, welcome to TALK OF THE NATION.

KEN: Hi. Hey, guys. Thanks for taking my call. One of the things that has happened here in St. Louis in the last couple of months is that they’ve incorporated a yellow – a blinking yellow light. And I just started seeing those, you know, the last couple of months. Then I’m realizing, people are like freaking out about this thing because they’re sitting at the light not wondering if they should turn or go or not. Some of them, you know, end up having to honk.

And then today, I noticed I was turning left and it was blinking yellow, and the two red lights on the right to go straight were still red. And I was like, God, you know, should I not go? You know, I felt kind of weird because the traffic coming on was still going. And thinking, well, you know, it was really – it’s just really confusing.

COX: I could only imagine that it would be. Thank you very much for the call. Let’s take another one, then I’m going to come back to you, Tom. We’ll talk some more about this idea, this – what is the name of it?

VANDERBILT: Diverging diamond interchange.

COX: The diverging diamond interchange. Before we do that, let’s talk to Amber ,who’s calling us from Detroit, Michigan. Hello, Amber.

AMBER: Hi. Thanks for taking my call. Here in Detroit, the Motor City, we have what’s called the Michigan left. And it’s, essentially, you turn right onto a one-way street and do a U-turn so you’re going the opposite direction. And there’s no left-hand turn.

COX: That’s because you have a U-turn in the middle of it. It’s a right and a U that end up becoming a left.

KEN: Exactly. And they’re very effective. People from other states say that they don’t use those stupid things where they come from, but we – we’re all about moving cars where they need to be efficiently, and it seems to work pretty well here.

COX: Well, thank you for that. What about that. You know, you do – actually, in the article that you wrote, one of them mentioned this. I don’t know that it’s always called a Michigan left, but that’s something that is used in other parts of the country as well. Right, Tom?

VANDERBILT: Exactly. That sort of pinpoints sort of what both callers were saying there is that, you know, drivers are basically resistant to change. And, you know, with good reason, engineers, you know, put out new solutions like this. They don’t do it lightly. They put a lot of research into it because, you know, people get used to driving in a certain way. You build up a muscle memory of how to drive. You’re suddenly asking someone to go on what they think of as the wrong side of traffic.

So before this first interchange was rolled out, it was tested in driving simulators for a number of years from the Federal Highway Administration. And, you know, they find that with proper signage, you know, people can get it. Just sort of show them what to do. And people always will say, you know, well, this looks so complicated. Why can’t we just go with the regular intersection? And a regular sort of four-way intersection may, you know, look simple.

But that simplicity, you know, sort of masks something which is going on there, which is that drivers often sort of let their guard down when they’re going through that. And this is why roundabouts are sort of a safer solution because – precisely because it feels a little bit more risky. You have to do a little bit more negotiating on your own. You’re a little bit more vigilant. And, in a four-way intersection, if you have a green light, your mind sort of shuts off and you’re not really looking for hazards from the side or someone who might have run a red light. So just this one cautionary note there.

COX: That’s an interesting point. If you’re just tuning in, this is not actually traffic school for people who have been cited for violating the traffic laws. We are talking about the left turn. And it is one of those maneuvers in driving that creates a great deal of problems. And the statistics show that a number of accidents – maybe not the majority of accidents but a large number of accidents – are the result of left turns. And our guest is Tom Vanderbilt, author of “Traffic: Why We Drive the Way Do and What It Says About Us.”

And we’re talking about a new way to make a left turn. Now, in describing it for you over the radio, it’s really hard to grasp the concept, which is why we have a website where you can go and see it. Just go to npr.org. Take a look at this and see what you think, and give us some feedback on it. Before we take another call, let me read a couple of emails that we have gotten. This one comes from Julia in Grand Rapids. It says, my strategy is simple: gun it and pray. Yikes.

Here’s another one from Paul This says, how does the diverging diamond differ from the single-point urban interchange? What about – now, I don’t know what the single-point urban interchange is. Do you, Tom?

VANDERBILT: Yes. But I fear that to try to describe the difference between those two would take us into probably another show and a level of complexity. But one difference is, as I understand it, this diverging diamond interchange is what’s known as a two-phase system – seen, again, we’re already getting into a complexity here. Let’s just say that the diverging diamond has been shown in studies to be more efficient and has a better safety record, also a bit cheaper to install than a single-point.

This is an important consideration when designing these large interchanges, especially over bridges. You’re looking to save as much money as possible and the divergent – diverging diamond has been shown to be about half the cost of traditional diamond interchanges and other types of intersections. So just another thing to keep in mind. But I fear we will lose even more listeners if we go into a…

COX: If we go into that. I’m going to ask you in a moment about the design that we were talking about, because it seems to me that it would work better in rural or suburban areas than it would in downtown Detroit or Manhattan or Los Angeles or even here in the District.

The single, biggest part of my left turn strategy is using my blinker. This comes from Jeff Arnold. The next part of my strategy involves watching the traffic flow and looking for turn alternatives. Ideally, I’ll make my left at a light, even if that means turning left a couple of blocks before or after my actual intended turn. If no light is available, then I’ll look for a break in the traffic which will let me turn across multiple lanes, a block or two before or after where I actually want to turn.

So it gets kind of confusing even for him. Let’s take another call. This is Peggy from Bentonville – is that Alaska or Arkansas?

PEGGY: Arkansas.

COX: Arkansas, OK. Welcome to the show.

PEGGY: Thank you. We have a traffic circle up in the house. It’s a new one and they’re putting in the Crystal Bridges Art Museum here in Bentonville. And so we’re going to have large volumes of people probably coming off bypass(ph), and that’s just one of the things they’ve included. In one access to them is then they have the traffic circle, and I really love using it. It’s actually fun to use, I think. I don’t know – I think that people proceed with caution when they approach it because they realize it’s something different. But – in any case, it works very well. It goes very smoothly.

COX: Well, thank you for the call. You’re listening to TALK OF THE NATION from NPR News. Let’s take another caller. This is Ian(ph) in – well, it just says San. I’m not sure what city you’re in California. Ian, where are you located?

IAN: That will be San Francisco.

COX: San Francisco, welcome.

IAN: Hey, thanks for taking my call. A couple of things. I ride a motorcycle, a car and a bicycle, so I’m kind of aware of the trickiness of intersections. The big thing for me is being direct and clear with your intentions. You know, it was mentioned earlier, making a left turn with a blinker makes a huge difference, also looking for eye contact from people coming towards you. You can see where about they’re looking if their windows aren’t tinted out, and that’s another thing that makes it a lot safer for me. I have some experience with the roundabouts in my old town and I love them. They’re fantastic. They work really, really well, and they’re really not that complicated. But the safety of them just makes a whole lot of sense, especially being on a motorcycle.

COX: Thank you, Ian, for that call. Let’s go to Gary, who is in Lawrence, Kansas. Gary, you are – oh, hold on. Hold on. There you are. Gary, are you there?

GARY: I’m here (unintelligible)…

COX: OK. Gary, you – this is Gary, right, from Lawrence?

GARY: No.

COX: No. OK. Well, tell us your name and where you’re calling from.

GARY: Lawrence, Kentucky.

COX: Oh, OK, Gary. Go ahead.

OK. I just have a couple of comments. The left-handed turn as opposed to the right-handed turn, it makes a lot of sense, you know, stopping left-handed turns. You run the risk of cutting in front of somebody. Also, you’re using more gas making left-handed turns than you are right-handed turns.

And why is that…

GARY: (Unintellligible) the intersection (unintelligible) turning lane, your engine is using gas and you’re not moving.

COX: Oh, I was going to ask you why…

GARY: (Unintelligible) turns.

COX: …why is that the case. You mean, when you’re idling, waiting to make a left turn?

GARY: Yeah, you’re idling, your car is not moving, but you’re still using gas.

COX: OK.

GARY: If you’re making a right-handed turn, you keep that flow going and, you know, it’s easier on the engine if you keep it going instead of just setting still, eating your own gas. I’m sorry.

COX: Gary, thanks for that call. Philip(ph) in Statesville, North Carolina, welcome to TALK OF THE NATION. You’re on the air.

PHILIP: Yeah, I appreciate the opportunity. I’m a motorcycle rider myself and left-hand turns cause a vast majority of conflicting traffic accidents between cars and motorcycles. And it’s the people that are turning left in front of you, obviously, become a pretty hard obstacle, so we don’t like them very much. I’m familiar with the various forms of intersections that you’re talking about, and I like every one of them. And if there was a way we can eliminate left turns, I’d happy for it – even people pull in from side streets onto the main thoroughfare, if they’re turning left, the last place they look before they turn left is to the left. And if a motorcycle is coming from the right, they won’t see that motorcycle and it winds up being a collision for the motorcycle and a whoops for the driver.

COX: Thank you very much for that call. This has been kind of interesting, Tom, hearing people talk about these left turns. Again, I want to remind people that they can go to see the idea that you and I were talking about at our website, npr.org. Really quickly, because we’re coming to end – the end of the program, what chance does this new idea have of becoming reality?

VANDERBILT: It’s quite popular. I mean, there have only been about a half dozen built to date, but there are basically many more sort of either in the works on the planning boards. And there’s about several dozen other sort of innovative intersection treatments that are on, you know, people’s sort of wish lists or in various stages of being drafted. But, you know, this is an issue that, you know, every place deals with.

And this diverging diamond isn’t right for every intersection treatment, just as a roundabout isn’t right. I mean, engineers will tell you that each specific location needs its own particular solution, but, you know, what they all share in common is this kind of age-old desire to eliminate this left turn or, you know, in some ways make it different…

COX: Got to stop it there, Tom, the clock says we got to go. Tomorrow, we’ll talk about calorie counts, new research showing the numbers on menus can be off. Tom Vanderbilt, thank you very much. We’ll talk about all of these things again tomorrow. This is TALK OF THE NATION from NPR News. I’m Tony Cox in Washington.

http://www.npr.org/2011/08/02/138930846/plan-eliminates-left-turns-in-u-s-intersections

A new kind of intersection eliminates dangerous, time-wasting left turns.

By Tom Vanderbilt|Updated Monday, Aug. 1, 2011, at 6:53 AM ET

“Every highway intersection is obsolete,” thundered Norman Bel Geddes—the designer and showman perhaps most noted for the Futurama exhibit at the 1939 World’s Fair—in his 1940 tract Magic Motorways.”The intersection is the chief stumbling block for highway designers and the chief headache for the traffic police,” he noted. “Why should the crossroads most heavily traveled today be the ones that are least adapted to the safe flow of the vehicles that use them?”

The question resonates today. In 2007, for example, the Federal Highway Administration reported there were 2.4 million crashes at intersections, representing 40 percent of all crashes, and one-fifth of all fatal crashes. Most intersection crashes fall under the category of “crossing paths,” and the most common path-crossing crashes, according to federal statistics, involve left turns.

Left turns are the bane of traffic engineers. Their idea of utopia runs clockwise. (UPS’ routing software famously has drivers turn right whenever possible, to save money and time.) The left-turning vehicle presents not only the aforementioned safety hazard, but a coagulation in the smooth flow of traffic. It’s either a car stopped in an active traffic lane, waiting to turn; or, even worse, it’s cars in a dedicated left-turn lane that, when traffic is heavy enough, requires its own “dedicated signal phase,” lengthening the delay for through traffic as well as cross traffic. And when traffic volumes really increase, as in the junction of two suburban arterials, multiple left-turn lanes are required, costing even more in space and money.

And, increasingly, because of shifting demographics and “lollipop” development patterns, suburban arterials are where the action is: They represent, according to one report, less than 10 percent of the nation’s road mileage, but account for 48 percent of its vehicle-miles traveled.

So what, perBel Geddes, can be done? What can you do when you’ve tinkered all you can with the traffic signals, added as many left-turn lanes as you can, rerouted as much traffic as you can, in areas that have already been built to a sprawling standard? Welcome to the world of the “unconventional intersection,” where left turns are engineered out of existence. This is not necessarily a new idea: The “Jersey Jughandle” and “Michigan Left” were early iterations of this concept; rolled out widely in the 1960s, both essentially require drivers to first make a right turn, then either looping back or U-turning their way onto the road onto which they had wanted to turn left.

One brute-force response is to simply build over an intersection. This is what happened at one intersection I know, the corner of Summerlin Road and Gladiolus Drive, in Ft. Myers, Fla. For years, it was a relatively innocuous four-way intersection with a single left-turn lane. My family and I used to stop every year at a small produce stand, Nancy’s, on the corner. But as the population of Lee County grew and traffic volumes increased, the intersection became increasingly congested. You were no longer assured of making it through on the first green “arrow”—and perhaps not even the second. And then, one year, as I approached the intersection, I saw a huge concrete loop—reminding me of the monolithic sandworm on the old paperback cover of Frank Herbert’s Dunerising out of the ground. There was no longer a left-turn signal—you simply whisked up the ramp, up and over the opposing traffic. There was just one drawback: It was absolutely hideous, like some looming relic of a phantom elevated superhighway. It was totally out of scale, even to the huge arterial roads that surrounded it. Nancy’s was a dim memory, the frontage it occupied presumably condemned for right of way.

“Grade separation” is the most extreme way to eliminate traffic conflicts. But it’s not only aesthetically unappealing in many environments, it’s expensive. There is, however, a cheaper, less disruptive approach, one that promises its own safety and efficiency gains, that has become recently popular in the United States: the diverging diamond interchange. There’s just one catch: You briefly have to drive the wrong way. But more on that in a bit.

(Get more stories like this one delivered to your inbox. Please sign up here for Slate’s daily newsletter.)

The “DDI” is the brainchild of Gilbert Chlewicki, who first theorized what he called the “criss-cross interchange” as an engineering student at the University of Maryland in 2000. (He eventually changed the name for fear of potential confusion with the singer of “Sailing.”) Inspired by a similar (and at the time, exceedingly unusual) design in Versailles, France, at the intersection of the Autoroute de Normandie and Boulevard de Jardy *, Chlewicki introduced his concept in a soberly titled paper, “New Interchange and Intersection Designs: The Synchronized Split-Phasing Intersection and the Diverging Diamond Interchange” (PDF) at an engineering conference in 2003.

The DDI is the sort of thing that is easier to visualize than describe (this simulation may help), but here, roughly, is how a DDI built under a highway overpass works: As the eastbound driver approaches the highway interchange (whose lanes run north-south), traffic lanes “criss cross” at a traffic signal. The driver will now find himself on the “left” side of the road, where he can either make an unimpeded left turn onto the highway ramp, or cross over again to the right once he has gone under the highway overpass.
An aerial view of the Dorsett Road diverging diamond interchange in Missouri. Click image to expand.
Aerial view of the Dorsett Road interchange

Perhaps counter-intuitively, this complicated approach is actually safer—and more efficient. What makes the DDI work is that it reduces the number of “conflict points” where traffic streams cross each other. There would usually be 26 such points in an intersection like this, but the DDI has only 14 (because, for example, drivers turning onto ramps no longer have to turn across oncoming traffic). But, as Chlewicki explained to me, not having those left-turn movements adds another advantage. In a standard “diamond” interchange, where traffic entering the highway has to turn across traffic, the two sets of traffic signals, because they have to account for the left-turn phase, are difficult to synchronize—which means cars wait in longer queues. But with the DDI, Chlewicki told me, “each signal in the interchange is only two phases, not three. And each of these two phases have some unique characteristics. The left turn from either ramp gets the same green phase as the arterial thru movement that does not conflict with that turn. It’s as if the design doesn’t need a separate ramp phase since it is built into the design.”

The DDI didn’t just go from Chlewecki’s presentation into asphalt. The concept was extensively tested on driving simulators by the FHWA’s Human Centered Systems team, who worried that “human errors due to unfamiliarity” might lead to more crashes (one suggested design element was a special “Keep Left” arrow, rather than the standard R4-8 “Keep Left” sign, which is more commonly used to signify “Keep Right”).

But drivers by and large got it, and in 2009, the nation’s first DDI went up in Springfield, Missouri. There are now any number of DDIs built or in the works, in states from Tennessee to Minnesota to Utah. Chlwecki admits they aren’t always appropriate; they don’t work well when traffic is equally heavy from opposing directions. Some truckers have pointed out that the design doesn’t allow one to exit the highway and then quickly re-enter by proceeding straight across the intersecting street to the next on-ramp (if one has to check calls, or has gotten off at the wrong exit). And aesthetically, like many large-scale engineering works, they are perhaps best appreciated from above. While the intersections are avowedly built with access for pedestrians and cyclists in mind, as this rather involved walk-through video of a DDI reveals, it doesn’t really feel like a human-scaled environment.

In a terrain that has been largely ruled by designs like the cloverleaf, the conventional diamond interchange, or, most recently, the early 1970s vintage single-point urban interchange—which was the only one to tackle the left-turn problem (though not as effectively, in cost or reduced conflict points, as the DDI)—there is presumably no end to the amount of intersection innovation still to come. One new solution, the “Continuous Flow Intersection,” is almost as common as the DDI itself. Chlewecki notes nearly three dozen alternatives to the traditional four-way junction, ranging from the “echelon” to the “windmill interchange” to the modern roundabout. (Like the DDI, the roundabout is often initially the subject of some vitriol from drivers; it could theoretically be used in place of a DDI, but doesn’t seem to perform as well for large interchanges).

But one wonders whether these new alternatives will eventually run up against the same problems faced by intersections with traditional left-turn lanes. In one Missouri study, a model that forecast traffic volumes at a DDI interchange in the year 2035 found that “two of the DDI models had slightly lower corridor travel times than those of the typical diamond interchange.” But here too is the limitation in the “predict and provide” mindset of traffic modeling: It presumes that traffic volumes will be much greater in 2035 because we will keep building houses with three-car garages, towns without sidewalks, eight-lane suburban arterials, and things like CFIs and DDIs to try to keep pace with traffic, rather than enabling and effecting more efficient pairings of land-use and transportation. While a fascinating engineering solution in its own right, the DDI is haunted by a lingering question: Can you ever truly design your way out of congestion?

Correction s, Aug. 1, 2011: This article originally misidentified the Boulevard de Jardy. ( Return to corrected sentence.)A photo caption on this article originally placed the Dorsett Road interchange in Springfield, Mo., and stated that it was the nation’s first diverging diamond interchange. The Dorsett Road interchange is near St. Louis, and it is not the first.

http://www.slate.com/articles/life/transport/2011/07/dont_turn_left.single.html

Left-Hand Turns Expose Difficulties of Elderly DriversPublished: 07/02/2007 Updated: 05/05/2009One study showed that failure to yield the right of way leads to more than half of the intersection crashes for which older drivers are responsible.

It’s intuitive as well as true: The toughest spots for senior drivers are intersections. That’s where most accidents involving elderly drivers occur, and where the most serious car crashes take place. Forty percent of the fatal collisions for people 70 and older occur at intersections and involve other vehicles, compared with just 23 percent of such crashes for 35-to-54-year-olds.

So intersections — and how and whether they can be modified in the interests of elderly drivers — are attracting increasing attention from researchers, advocacy groups and government agencies.

The challenges posed by crossroads also apparently are getting more attention from senior drivers: Fatal crashes at intersections declined dramatically in a new study by the Insurance Institute for Highway Safety that showed a 21-percent decline in crash deaths among drivers 70 and older in the decade ended in 2006.

The Problem With Left Turns
The most extensive and recent research on traffic intersections has shown that senior drivers flirt with many sources of danger near, at or within intersections. One of them is a higher tendency to run into cars in front of them. But by far, the inability to safely execute an unprotected left-hand turn — one without a left-turn signal — is their stiffest challenge.

To be sure, left turns are dangerous for everyone. So at thousands of major intersections across the country, they’re protected by a green arrow. Some places try other approaches. In Michigan, for example, the locally infamous “Michigan left-hand turn” requires a driver who wants to turn left to first make a right turn, then make a legal U-turn in the median strip.

Unprotected left turns present one of the most hazardous scenarios in routine traffic. “It’s a relatively complicated situation for any driver, because you’re processing multiple sources of information and having to make multiple decisions, such as judging the speed of the oncoming vehicle or vehicles, how quickly you can react and so on,” said Anne McCartt, senior vice president for research at the Insurance Institute for Highway Safety (IIHS).

But because of the specific challenges older drivers face and the particularly complex dynamics of traffic movements through an intersection, elderly drivers are especially bad at navigating unprotected left turns. Each advancing year of age after 65 increases by 8 percent the odds of getting into a crash that involves turning left, according to a 2002 study by University of Kentucky researchers.

“Older drivers aren’t speeders or DUI,” said Elinor Ginzler, director for livable communities for the AARP. “But they have more problems with left-hand turns. And the way that most left-hand turns are designed, it accentuates the problematic ability of the older driver to do that.”

Failure to yield the right of way to other vehicles led to more than half of the intersection crashes for which drivers 80 or older were responsible, according to a newly released IIHS study of Connecticut intersection crashes in 2003 and ’04. This compared with about one-third of the intersection crashes even for 70-to-79-year-olds and about a quarter of those involving 35-to-54-year-olds.

Stop signs are more of a culprit than traffic signals. Fifty-nine percent of failure-to-yield crashes occurred at stop signs in the Connecticut study, and 50 percent of those crashes occurred while motorists were turning left — for all age groups.

The physiological and mental ravages of aging appear to be largely responsible for older motorists’ exaggerated problems at intersections. Vision deterioration impairs elderly drivers’ ability to see other vehicles that may be relevant to them in all directions, even behind them. Cognitive challenges mean they often can’t make decisions fast enough, especially about whether and when to make a left turn ahead of vehicles that may be approaching from the right. And declining physical dexterity impedes their ability to execute decisions.

“Often they can’t judge the time until there would be contact with an approaching vehicle, and their decision about what a safe gap is means that seniors delay longer and longer before entering traffic and feel more and more anxiety until they do,” said Richard Backs, a psychology professor and expert on driving vision at Central Michigan University. “But it doesn’t make them safer because at some point they still have to execute the turn.”

Making Intersections Less Dangerous
Road designers and senior-driving experts agree that, when it comes to intersections per se, two main types of improvements would help significantly. One of them is making protected left-hand turns ubiquitous, wherever possible, at intersections governed by traffic signals. That way, older motorists don’t have to make the most problematic decisions about when to proceed.

A second popular suggestion is to build more traffic circles, or roundabouts. They are common in Europe but not so numerous in the United States, although more are being constructed all the time. Research by the IIHS identified three major advantages of roundabouts that combine to dramatically reduce the potential for serious car crashes, compared with conventional intersections. Each of these pluses of roundabouts is particularly helpful to older drivers.

The first safety edge is that all drivers are proceeding in the same direction. The second: Everyone is traveling at very low speeds. The third advantage is that traffic circles eliminate head-on and right-angle crashes that tend to be the most destructive.

“We recognize that, when they’re first constructed, traffic circles can be confusing for all ages because they’re still so rare in this country,” said McCartt of the IIHS. Moreover, roundabouts aren’t without their own dangers, “because you don’t have the security that you may feel at an intersection where there is a stop sign or a stop light and then you go.”

But over time, McCartt said, “Drivers are much more in favor” of traffic circles as they get used to them.

Another useful approach is to remind senior drivers that a certain amount of caution, as in all driving, can be a good thing at intersections. For example, in an AARP driving-improvement class they teach in Michigan, Jack and Nancy Stegeman stress that the law emphasizes “yielding” to other motorists rather than asserting “right of way.”

“It’s just safer to think that way,” Jack Stegeman said.

http://www.edmunds.com/car-safety/aging-drivers-intersections-are-danger-zones.html?articleid=121524

By Frank Kalinski
Expert Author Frank KalinskiMaking a left hand turn is one of the most dangerous maneuvers you attempt while driving your car. It can also be the deadliest because you are exposing the thin, weak sides of your car to oncoming traffic; airbags and seatbelts are much less effective in these left hand crashes. Green left turn arrows, roundabouts and “Michigan U-turns” are becoming more popular at busy intersections and safety is improving. But there are many times when you must make a left turn across many lanes of traffic.Or do you?United Parcel Service now routes all their trucks to make right turns only:”UPS’s routing software shaved 20.4 million miles off their routes last year while delivering 350,000 more packages.” and “Turning right decreases safety hazards and delays. If a driver is stuck waiting for traffic to pass with a left blinker on, it’s going to set them back. Jutting out into traffic is also a good way to get side-swiped, especially when driving a big truck” according to Bob Stoffel, Senior VP of UPS.

Think about your neighborhood and subdivision and your route to work, the grocery store and school. Instead of making a beeline to the main road where you must make a left turn, can you go the opposite way and make two right turns to get out to the main road? This may seem like a waste of time and fuel but according to the UPS study you will not wait as long idling your engine while waiting to make the left turn.

We live in a “grid style” subdivision so it’s easy for me to drive a few blocks on residential streets to where the traffic light is. I can then make a left turn under the protection of a traffic signal. Modern subdivisions with curving-winding streets and cul-de-sacs may be more difficult but explore other routes, you may find a path to a traffic signal or where you can make a right turn.

And how about the mall and grocery store? Before you go shopping next time think about your route and the traffic signals in and out of the area. Can you drive to the store and back home again making all right turns? Major shopping areas with restaurants and theaters will have their own traffic signals with green left turn arrows to protect you from traffic. Use the roadways inside the parking area to get to a traffic signal and then make your turn onto the main road.

Many intersections have gas stations, convenience stores or banks right on the corners adding even more danger and complexity to your trip. Have you seen people making a left turn across three and four lanes of traffic trying to get in or out of a gas station? If you get into an accident while making a left turn you will almost always be at fault because left turn traffic is expected to yield to all through traffic. Take a look at the lane stripes close to any intersection. You will see a “double yellow line” which under any circumstance you must not cross. Turning right into or out of these locations is your only legal choice.

The vast majority of our trips in the car are to same places day after day. With little effort we can find new routes avoiding dangerous left hand turns. In just a few weeks these will become habits that will not only save fuel and time but increase the safety for us and our families.

Frank Kalinski has driven trucks and passenger buses since 1974. An advocate for better transit, pedestrian and bike safety he has been working in the Detroit area to improve fair and safe access to roadways for bikes, wheelchair users and pedestrians.

Article Source: http://EzineArticles.com/?expert=Frank_Kalinski

http://ezinearticles.com/?You-Can-Become-a-Safer-Driver-by-Avoiding-Left-Hand-Turns&id=6833551

By Dan Farber | November 22, 2005, 10:36am PSTUPS does IT on a very large scale: $1 billion in IT spending this year, nearly 5,000 IT staff, 384,000 employees, 15 mainframes, 8,700 servers, 250,000 PCs, 2,700 networked sites, 474 terabytes of storage, 500 applications, 10 million tracking requests per day, 88,000 vehicles, 90,000 handheld devices and the 9th largest airline. The massive array of technology and personnel is all focused on delivering more than 14 million packages a day across 200 countries. Last week I interviewed UPS CIO Dave Barnes Watch the video about managing IT on such a large scale and getting a return on tech investments.UPS CIO Dave Barnes shows me the latest DIAD (Delivery Information Acquisition Device). The actual units are brown, of course.

Barnes, a 29-year veteran of UPS who started sorting packages while in college, told me how UPS expects to save $600 million per year through package flow technologies, which will enable a reduction of 100 million travel miles in the U.S. alone, which equates to 14 million gallons of fuel, he said. The package flow optimization includes constant wireless communications via the DIADs, smart labels (including RFID in the future) and preloading vehicles and directing drivers according to advanced analytics that calculate the most efficient routes, including avoiding left-hand turns, based on the package load.

http://www.zdnet.com/blog/btl/ups-driving-cost-savings-by-eliminating-left-hand-turns/2190

By BRIAN ROONEY
GARDENA, Calif., April 4, 2007Efficiency is everything for United Parcel Service. Save time, space and money, and get there when promised.Throughout the UPS system, computer-sorted packages marked with special codes race along conveyors to trucks precisely loaded by address and order of delivery. Not satisfied with grocery-store bar code, the company invented its own — made up of clusters of dots in a circle its employees call “ups” code.But UPS has one low-tech secret to getting deliveries there on time. Listen to driver Bert Johnson describe his route in Gardena, Calif.”We’re gonna make a right turn onto 135th to Western. We’ll make another right on Western down to 139th,” Johnson says. And he goes on, “Right turn on 139th and go down to the end of the block and we’ll make another right turn.”

You getting the idea? UPS plots its delivery routes to make as many right turns as possible. In a world where half the driving choices are left turns, they avoid turning left.

And how much of the time are UPS trucks turning right? Tasha Hovland, an industrial engineering manager, said, “A guesstimate, I would probably say 90 percent. I mean we really, really we hate left turns at UPS.”

Efficiency is so much a part of the culture at UPS that to save space inside the dispatch centers the signature brown trucks are even parked just five inches apart with rearview mirrors overlapping.

Right Turns Forever

Making right turns has been the way of UPS since before anyone now working for the company can remember. UPS managers used to get out and drive the routes, plotting on maps how they could be efficiently driven turning mostly right. Now they have a combination of not just experience, but computers, codes and programming that allows them to plot out right-turn routes in minutes.

Johnson sees the difference. “I do drive a lot fewer miles,” Johnson said. “I was driving 35 miles at first. Now I’m down to 30 miles a day.”

UPS trucks drove 2.5 billion miles last year, but the company says its package flow technology combined with right-turn routes saved 28,541,472 million miles, and three million gallons of fuel.

The company puts almost 92,000 trucks on the road every day. But without its efficiency and right-turn routes, it would have to send out an additional 1,100 trucks.

It’s not that trucks never turn left, but they’re always looking for ways to avoid it. And UPS employees tend to take the philosophy home.

Jim Winestock, a UPS vice president in Atlanta, said, “I know it drives my wife crazy, but I’ve been known to pass up drug stores, three or four on the left-hand side of the road, just to get to the one on the right-hand side of the road.”

Back with Johnson, the California UPS driver, he keeps describing his route. “Right turn here on Cimarron, to the next driveway and we’ll make a right into that.”

http://abcnews.go.com/WNT/story?id=3005890&page=1#.T7xFIlKM5Bk

by Paul Michael on 12 December 2007

You have to hand it to UPS. They crunched the numbers, they looked at the hard facts and they figured out that by limiting the number of left-hand turns made, you can save a whole bunch of money on gas.

UPS

Joel Lovell of the NY Times revealed on Sunday that the UPS has significantly cut down its gas usage by carefully calculating routes to avoid left-hand turns. Not every left turn of course, that would be ridiculous. But by employing a program called “package flow” the fleet of over 95,000 trucks can now avoid a massive number of left-hand turns, taking only the ones necessary to complete the trip.

As you’re no doubt aware, left-hand turns are far more costly because of the waiting time involved. There’s rarely a “left on red” rule and thus drivers have to idle, wait for the lights to change and burn up gas. Depending on the cross street, that can take up considerable time and fuel. The “package flow” program has put an end to most of that, and has also saved time and mileage in the process.

As always, the proof of the pudding is in the eating. And these results are very tasty. Last year UPS shaved over 28.5 million miles off its delivery routes. That in turn has resulted in saving roughly three million gallons of gas! It’s also reduced CO2 emissions by 31,000 metric tons. This is an example of lateral thinking at its best. It saves time, money and the environment, and everyone is a winner.

GPS

Those of you with those handy GPS navigation devices may want to think about doing something similar on your drive to work. If you can cut out the left-hand turns without eating up any extra miles or time, you could see a nice drop in your fuel bill. With the cost of gasoline still over $3 a gallon, that could add up to quote a nice pile of extra cash every year. Now, I’m off to send my holiday packages via UPS.

http://www.wisebread.com/save-gas-dont-make-left-hand-turns

By JOEL LOVELL
Published: December 9, 2007It seems that sitting in the left lane, engine idling, waiting for oncoming traffic to clear so you can make a left-hand turn, is minutely wasteful — of time and peace of mind, for sure, but also of gas and therefore money. Not a ton of gas and money if we’re talking about just you and your Windstar, say, but immensely wasteful if we’re talking about more than 95,000 big square brown trucks delivering packages every day. And this realization — that when you operate a gigantic fleet of vehicles, tiny improvements in the efficiency of each one will translate to huge savings overall — is what led U.P.S. to limit further the number of left-hand turns its drivers make.The company employs what it calls a “package flow” software program, which among other hyperefficient practices involving the packing and sorting of its cargo, maps out routes for every one of its drivers, drastically reducing the number of left-hand turns they make (taking into consideration, of course, those instances where not to make the left-hand turn would result in a ridiculously circuitous route).Last year, according to Heather Robinson, a U.P.S. spokeswoman, the software helped the company shave 28.5 million miles off its delivery routes, which has resulted in savings of roughly three million gallons of gas and has reduced CO2 emissions by 31,000 metric tons. So what can Brown do for you? We can’t speak to how good or bad they are in the parcel-delivery world, but they won’t be clogging up the left-hand lane while they do their business.http://www.nytimes.com/2007/12/09/magazine/09left-handturn.html

Dina Spector|March 15, 2012

This series on Sustainable Solutions is brought to you by UPS.

With gas prices soaring, drivers are scoping out every opportunity to save at the pump.

One possible solution: avoid making left-hand turns.

The fairly simple idea — and well-known delivery strategy of UPS — addresses the fact that idling while waiting to turn against oncoming traffic wastes time, and by extension, fuel and gas money.

But does the theory hold water?

According to Dr. Joe Hummer, a professor of civil, construction and environmental engineering at NC State, minimizing left turns is fuel-efficient in a couple of ways.

In 2011, Hummer was part of study to determine whether superstreet intersections in North Carolina result in faster travel times. At a superstreet, all left-hand turns from side streets are re-routed so that drivers must turn right and then make a U-turn.
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Researchers found that compared to conventional traffic designs, superstreets reduced travel time by 20 percent overall. According to Hummer, travel time is proportional to fuel use.

At some intersections the delay for left-turning vehicles is so long that those drivers will save time and gas by finding some other way, such as making three right turns, Hummer explains.

Protected green arrows also take time away from through traffic. Many cars are waiting and burning gas while only a few cars are moving.

“If fewer people made left turns, the signal controller could take time away from the green arrow and give more time to the green ball for through vehicles and right turn vehicles,” said Hummer. “Since there are typically many more through vehicles than left-turning vehicles, the net effect would be fuel savings.”

http://articles.businessinsider.com/2012-03-15/news/31195555_1_fuel-savings-green-arrow-travel-time