Engineers working toward a world without left turns

THRILLHO

Registered User
Apr 5, 2009
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#1
I wan go home


Traffic engineers are working to design traditional left turns out of existence, calling them the "weakest links in the system."

"Left turns are a big issue with intersections," said Brian Walsh, State Traffic Design and Operations Engineer for the Washington State Department of Transportation. "Of the 7 million crashes that occur on the system nationally, 2.4 million of those crashes occur at intersections. What do we take care of at intersections? Mostly left turns."

While they can't get rid of them, UPS is already in the business of bypassing them. In fact, the shipping giant spends a billion dollars a year on software that helps to avoid left turns.
"It's based on algorithms and technology, but it boils down to two words: network optimization," said Susan Rosenberg, Spokeswoman at UPS headquarters in Atlanta. "UPS does minimize left turns for efficient routing. You're coming to hard stop, you've got to make a left turn, you're going to be idling at your stop that's burning fuel. That's taking time. You've got more of a safety impediment than if you were just taking a right turn."

But, if left turns simply didn't exist, UPS wouldn't have to spend so much time and money trying to avoid them. That's why traffic engineers are working on new intersection and interchange designs that will solve the problem.

One of the newest solutions - that is used mainly at interchanges with high traffic volume - is something called a diverging diamond interchange. There are only six of them in use nationally.
"It's kind of counter initiative, but on the cross streets - the street that passes over the freeway for an example - they flip everybody right prior to the interchange onto the left side of the roadway," Walsh said. "So you're actually driving on essentially the wrong side of the roadway like the English would."

The design allows a driver to merge onto the interstate without having to stop at a signal or take an
unprotected left turn. WSOT is considering building such an interchange at I-90 and Barker Road in Eastern Washington.

While the system can't be redesigned overnight, Walsh said they try to find an easier way to make left turns every time they build, or rebuild, an intersection."Trying to handle left turns a better way is why we're coming up with, nationally, a lot more innovative type of designs, he said. "The diverging diamond interchange, the indirect left turns type of intersection, they're all there to try to handle left turns safe as well as bit more efficiently."
Still no word on whether or nor three rights make a left.
 

Neon

ネオン
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Mar 23, 2008
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#2
Just make getting a driver's license hard, instead of so easy that a blind retard can get one. Problem solved.
 

BIV

I'm Biv Dick Black, the Over Poster.
Apr 22, 2002
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#7
Diverging diamond interchange:



 

Turfmower

Registered User
Jan 17, 2005
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#8
The same idiots probably came up with the concept of the roundabout.
Traffic circles Rule it better than waiting a a light. the only thing that messes them up is when you get dummies from the midwest that don't have a clue how they work, I go around the Somerville Circle 5 to 6 times a day.
 

Turfmower

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Jan 17, 2005
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#9
Points and Laughs @ mkrochmaln Location sylvania,ohio
 

DanaReevesLungs

I can keep rhythm with no metronome...
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Jun 9, 2005
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#11
Springfield, MO already has one in place.

[yt]B5JtZMPTNAY[/yt]
 

weeniewawa

it's a man, baby!!!
May 21, 2005
12,076
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#12
I hate roundabouts. Just drove through colorado awhile ago. They seem to love those stupid things there.
some consultants are going around to every city in the country and getting them to put those in

and when they figger out they lose the revenue from people running red lights, they will take them out
 

mkrochmaln

Well-Known Member
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Jun 14, 2006
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#18
some consultants are going around to every city in the country and getting them to put those in

and when they figger out they lose the revenue from people running red lights, they will take them out
Think your right about that. I've been driving truck over the road eight years now. My least favorite roundabout is in st.George Utah,Heading south on I-15 at exit 4. On the east side of I-15 is the pilot truck stop. The south bound I-15 exit ramp puts you on the west side of I-15. You have to almost do a figure eight to get to the pilot,all the while doing multiple lane changes. In a car no big deal,but pulling a 53 foot trailer and having to quickly change lanes puts the four wheelers at risk of getting flattened by my trailer. Luckily I've not had an accident that has been my fault. Been hit a couple times, I was not a fault in those.
I can see where people can think roundabouts save money by keeping traffic moving and not sitting idle at a light.
To each his own I guess. I'm just not a roundabout fan.
 

lajikal

Registered User
Aug 6, 2009
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#19
I can see where people can think roundabouts save money by keeping traffic moving and not sitting idle at a light.
To each his own I guess. I'm just not a roundabout fan.
Roundabouts are good. People will move out of your way or learn to. They will cut back on old folks and timid drivers on the roads. Europeans got one thing right.
 
Dec 8, 2004
49,036
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#20
Roundabouts are good. People will move out of your way or learn to. They will cut back on old folks and timid drivers on the roads. Europeans got one thing right.
Yep especially the wacky intersections they have around here like 5 roads intersecting at weird angles..

Like:



And yep people from certain states deff do not know how to use them...
 

Creasy Bear

gorgeousness and gorgeousity made flesh
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Mar 10, 2006
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#21
Traffic circles Rule it better than waiting a a light. the only thing that messes them up is when you get dummies from the midwest that don't have a clue how they work, I go around the Somerville Circle 5 to 6 times a day.
I live in the roundabout capital of the world(in the midwest), and the only people I see who can't figure them out are the Chineezers.


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