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Ever danced the Hokey Pokey at a wedding reception?
You know . . . Put your left foot in, put your left foot out. Shake it all about.
Good. Then you’ll be ready for what Colorado Springs traffic engineers have in store when they rebuild the Interstate 25 interchange at Fillmore Street.
The reconfigured interchange, as planned, will introduce a whole new dance step for drivers and it’s not unlike the Hokey Pokey silliness.
The plans call for construction of a “diverging diamond” interchange.
This graphic shows traffic flow in a "diverging diamond" interchange. Traffic on the Fillmore Street Bridge would follow a similar pattern as shown here.
Interstate 25 and Fillmore Street as seen from GoogleEarth. Under the Diverging Diamond configuration, the interchange would be simplified because Chestnut Street will be realligned to the west and no longer intersecting with the southbound I-25 exit-entrance ramps.
Not a familiar driving term?
Don’t feel bad.
Most of the world’s driver are immune to it.
But just as the once-obscure “round-about” has become more common in our driving vocabulary (as in “these freaking round-abouts drive me freaking crazy”), so, too, will “diverging diamond.”
Soon, actually, if the city lands a $10 million federal grant to pay for a makeover of the interchange, says Kathleen Krager, senior city traffic engineer.
Rebuilding the interchange is too expensive. so the old bridge will remain. But that’s about all that will stay the same.
Ty Pennington of ABC's Extreme Makeover: Home Edition.
What Krager described to me sounds like an extreme makeover. All that will be missing is the annoying guy with the spiked hair, soul patch and megaphone.
There will be, I fear, plenty of people shouting “Move that bus!” because the diverging diamond looks pretty confusing.
Here’s how it will work.
Motorists on Fillmore will criss-cross each other, just as they approach the bridge over I-25.
The manuever will look just like my kids’ electric slot car race track where the cars duck back and forth across the tracks. (Of course, this usually creates spectacular slot-car crashes.)
There will be traffic signals preventing spectacular crashes on Fillmore.
Hopefully.
This is a screen-capture from an animated fly-through created by Fisher Associates, a New York engineering firm.
For example, westbound traffic on Fillmore will cross onto the far left lanes, or south side, of the bridge. In other words, traffic will be traveling on the wrong side of the bridge.
Same for the eastbound cars. They will shift onto the north lanes to cross the bridge.
Krager said the beauty (huh?) of the diverging diamond is that it creates no-wait exits onto the interstate.
Westbound drivers, for example, will leave a traffic signal, move to the wrong side of the bridge and have a smooth left turn onto southbound I-25 before the traffic crosses back onto the normal side of the road.
“It removes the left turns that cause conflict,” Krager said. “Everything becomes right turns.”
This link takes you to an animated flyover that explains the diverging diamond.
Click here to see another more rudimentary animated interchange.
The diverging diamond is debated on this Minnesota website and includes actual video of a diverging diamond in action.
Like I said, it’s just like doing the Hokey Pokey where turn yourself around.
That’s what it’s all about.
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Bill, I fear this may end up more like “Simon Says” than the Hokey Pokey, although that’s a dandy analogy.
I live in this area and I have a personal solution. I’ll either use Garden of the Gods or Fontenaro to get on, off and across the interstate.
The theory of this pattern is sound. In practicality, with real drivers, distractions, sun glare, traffic congestion, etc. etc. … it’s going to be a death trap.
I hope they are going to lengthen the southbound exit from I-25. You shouldn’t have to start breaking before you reach the exit. I’m always afraid I’m going to be rear-ended making that exit. It makes me feel like I’m landing an airplane on an aircraft carrier. Maybe they should install arresting wires to help drivers stop in time.
This interchange is WONDERFUL!!! They just installed a second one of these in Springfield, MO where I just visited. It takes a few times through to get comfortable, but it really smooths out traffic for on and off ramps. The first one is at the main entrance on the north side of town that was always jammed up (even has a Walmart on the corner – semi traffic all the time). It is smooth as silk! Congrats to Colorado Springs to join the trend! (I believe this design originated in Europe.)
I use Garden of the Gods even though I technically live closer to the Fillmore exit because the Fillmore interchange, as it sits now, is a hot mess, with cars backed up all the way into the right-hand lane of Interstate 25 during the evening rush hour.
This money should be saved until they can afford to rebuild the interchange. The bridge is already in terrible shape, it will most likely have to be reinforced or rebuilt in the next 25 years anyway. With the addition of centennial blvd connecting through to the top of Fillmore hill and the adjacent ever-growing housing development there will be far more traffic in that immediate area in the not too distant future. Reference the Nevada/Tejon/I-25 interchange to see how competent our traffic engineers are nowadays. I fear this will end up being just as big of a failure, costing the city countless millions of dollars in the long run.
Looks interesting, but the statement that it eliminates left turns is insanely false. According to your diagram you have to make a left turn at a light to get on the other side? How is that any different from making the left turn at the other end of the overpass other than it is not at 90 degree turn?????
It eliminates the waiting for oncoming traffic to clear for left turns.
This interchange is not as bad as the reporter thinks. You drive through it without suspecting anything, and only after you have gone the way you wanted to do you say “what just happened?”