QuoteThe article is from last year, I'm surprised it didn't get more press...
QuotePlans by state transportation officials to install "movable" toll lanes to reduce morning gridlock along I-20 in South DeKalb are being praised by some but also renewing questions about whether the long-promised MARTA rail line along the corridor will ever become a reality.
On June 14, the Georgia Department of Transportation sent a letter to DeKalb County commissioners, informing them that it intends to construct "a tolled movable vehicle barrier separated lane on I-20 westbound from Panola Road to Columbia Drive" — a 5.2-mile stretch of the highway.
www.crossroadsnews.com/news/local/movable-toll-zipper-lane-planned-for-i/article_0941bb0e-7992-11e8-9439-8b12bf782ccb.html
Interesting. I've only seen this used in one other place: Interstate H1 on the west side of Honolulu (https://www.google.com/maps/@21.3906427,-157.9636954,3a,75y,222.87h,66.35t/data=!3m6!1e1!3m4!1sH0sFI8N9jPZ9r6DoMOjbZg!2e0!7i13312!8i6656). Hard to say how well it worked, as there was also ongoing construction at the time I was driving through.
Dallas has (or at least had) one on I-30. I used to drive thru the area in the 1990's (IIRC) and the machine was often not working for whatever reason. It felt like such a boondoggle at the time. It was pretty cool to watch the zipper machine in action.
From a very cursory glance on line, looks like it's still in use.
Doesnt the Golden Gate bridge have a movable barrier?
Quote from: US 81 on October 09, 2019, 11:23:48 AM
Dallas has (or at least had) one on I-30. I used to drive thru the area in the 1990's (IIRC) and the machine was often not working for whatever reason. It felt like such a boondoggle at the time. It was pretty cool to watch the zipper machine in action.
From a very cursory glance on line, looks like it's still in use.
Drove in on I-30 this summer, and it was being used for outbound traffic during PM rush hour. Assume it reverses in the AM for inbound traffic.
Quote from: Georgia on October 09, 2019, 07:11:10 PM
Doesnt the Golden Gate bridge have a movable barrier?
Yes.
The peak direction has 4 lanes, and the off-peak direction has 2 lanes. In the AM, it faces inbound to San Francisco, and in the PM it faces outbound.
The Walt Whitman and Ben Franklin Bridges between Philly and NJ have movable barriers that are moved twice a day: 4 lanes into Philly with 3 going into NJ on the morning...and the opposite in the afternoon. The barrier is moved either after the morning rush or mid afternoon depending on construction on the bridge during the day. At night, it's often moved just after rush hour, but if there's an Eagles game or some other big event in Philly it's moved sometime between 2 and 5am. The travel lanes right next to the barrier are kept open while the zipper machine moves the barrier.
The Commodore Barry Bridge has a zipper barrier too, but it's not moved unless necessary, usually due to construction.
The Coronado Bridge in San Diego has a movable barrier. It alternates 2 and 3 lanes in each direction
Although it was temporary, I-15 had one of these north of Salt Lake City (https://goo.gl/maps/NuR3uSyByDzEUYTS7) when it was reconstructed between 2008 and 2010.
Quote from: kendancy66 on October 09, 2019, 11:40:01 PM
The Coronado Bridge in San Diego has a movable barrier. It alternates 2 and 3 lanes in each direction
There's also one on the I-15 fast lanes north of SD. It alternates three southbound lanes in the morning, two lanes each way all other times.
Chicago did this decades ago on Lake Shore Drive and on some arterials. The arterial lane changes were directed by overhead been and red lights over the lanes.
LSD lanes were separated by little concrete lane barriers that would come up and down out of the road between the lanes.
The problem was they were only a foot high and drivers would cross them and there were lots of deadly crashes.
That isn't the issue here but a five mile moving operation might cause it's own traffic issues?
Quote from: 3467 on October 10, 2019, 09:40:18 AM
Chicago did this decades ago on Lake Shore Drive and on some arterials. The arterial lane changes were directed by overhead been and red lights over the lanes.
LSD lanes were separated by little concrete lane barriers that would come up and down out of the road between the lanes.
The problem was they were only a foot high and drivers would cross them and there were lots of deadly crashes.
That isn't the issue here but a five mile moving operation might cause it's own traffic issues?
The machine runs about 5 mph or so, so you're talking about an hour's time. While there may be some traffic issues at first as traffic slows down to watch the machine, or the agency closes the lane of traffic close to the machine, over time the congestion clears up as people get used to the equipment and lane closures aren't necessary. The worst is if the machine breaks down and they can't repair it in time, which is why moving the barrier just after traffic subsides is better than moving the barrier just before the lane is needed, as there's time to make the repairs.
Outside of this toll zipper lane, are there any plans to eventually add full two-way managed lanes to the Interstate 20 corridor (such as one or two toll lanes in each direction)? Or would right-of-way impacts be too great for such an endeavor?
Quote from: The Ghostbuster on October 10, 2019, 01:32:58 PM
Outside of this toll zipper lane, are there any plans to eventually add full two-way managed lanes to the Interstate 20 corridor (such as one or two toll lanes in each direction)? Or would right-of-way impacts be too great for such an endeavor?
There are no plans for tolls on I-20 as far as I know and ,even if there were, GDOT would probably only put 1 lane each direction :banghead:
Ha, just now saw this. There's no room for an additional lane in either direction under the bridges at Columbia Drive, I-285 (three of them), Miller Road or Panola Road. There is room under Wesley Chapel Road, but... there was no depiction or discussion of this ridiculous concept at the public information meeting for the I-20-285 interchange, the video for which covered all the way out to Lithonia Industrial. What are these people even thinking?
I'm glad this plan was scrapped. I also believe that the ramp from 285 NB to 20 East needs addressing. The traffic especially from trucks causes it to back up to Flat Shoals road...
the whole interchange is supposedly getting redone sometime this decade, same with the 20-285 interchange on the west side.
Only 2 flyovers will be added to the 285/20 interchange in dekalb county and a CD format from the Snapfinger creek. That interchange isn't being redone, even though it surely needs it! Because C/D enter and exits could be implemented at Columbia Dr. Glenwood Rd and Flat Shoals rd...
Quote from: US 81 on October 09, 2019, 11:23:48 AM
Dallas has (or at least had) one on I-30. I used to drive thru the area in the 1990's (IIRC) and the machine was often not working for whatever reason. It felt like such a boondoggle at the time. It was pretty cool to watch the zipper machine in action.
From a very cursory glance on line, looks like it's still in use.
The one in Dallas is still in use. It actually was extended about ten years ago.