Atlanta

[Tom958]

Double post! 

Another GDOT signage screwup, this one on I-285 eastbound. The exit to 141 southbound has a decel lane (hopefully you can discern the taper) which is incorrectly signed as a lane drop. The one to 141 northbound is a lane drop-- note the solid painted line-- but is signed as optional. The lanes were once striped as the signage indicates, but a couple of years ago, the current (and better) scheme was introduced. As you might have guessed, the old compressed font signage was recently replaced, but apparently the new signs were designed the same as the old ones-- nobody bothered to check the field conditions, even though a GDOT field office is less than three miles away. 

[Tom958]

Atlanta.curbed. com has an article about the 285-400 interchange, and they've posted some better photos.

I already mentioned that the fifty year old bridges carrying Roswell and Ashford Dunwoody Roads over 285 will remain. As I look more closely, I'm realizing to my horror that apparently the bridges carrying I-285 over Glenridge, Peachtree Dunwoody and what is now the northbound roadway of 400 will also remain. I don't see even incidental changes to the layout under the bridges at Glenridge or Peachtree Dunwoody, and the new alignment of the ramp from 285 westbound to 400 northbound appears to be the flattest curve that can be accommodated under the existing bridge carrying 285 once the loop ramp is relocated to between the end bent and the abutment.

Frugality is a Good Thing, of course, but I don't understand how the 285 wing of the project can possibly cost over $700m given the relatively limited scope. 

[Tom958]

Quadruple post!    I can't help still wanting to talk about 285-400, even if nobody else does. A few observations:

I hijacked those photos from here, and they display better there.

Check out the access from Ashford Dunwoody to GA 400: there's a two lane onramp that continues onto I-285 westbound, and a single lane ramp branches off to join the two lane ramp from eastbound 285 to 400. After a rather short left-side weaving section, the ramp splits: one lane left for southbound 400, two lanes right for northbound. This configuration reminds me of the connection (actually, the lack thereof) between Chamblee Tucker Road and I-85 a few miles east of here. A similar left-side merge was planned and mostly built, but it was apparently decided during construction that there'd be too much weaving in not enough room and possibly that the unusual decision point on the Chamblee Tucker onramp would lead to confusion and last-second swerving, so the short slip ramp from the Chamblee Tucker onramp to the I-85 ramps wasn't built, and traffic from Chamblee Tucker near I-285 must access I-85 by using surface roads to other service interchanges on I-85. After spending over $1 billion, might the same thing happen here?

The reason that the weaving section is so short is because the flyover ramp from eastbound 285 to southbound 400 needs to be really high. I'm a bit surprised that the ramp is depicted in the rendering as being on fill between retaining walls rather than on structure. I hope that the flyovers will be constructed of something more aesthetically pleasing than AASHTO girders, but based on recent history I'm not optimistic. 

Speaking of that flyover, I think that it'll have to be completed fairly early on. The new mainline bridges for 400 over 285 can't be opened until the existing ramp from eastbound 285 to southbound 400 is out of the way, and at least one of those bridges will need to be open as a detour during demolition and replacement of the existing 400 southbound roadway over 285.

And, speaking of short weaving distances, check out the movement from Glenridge Connector to 400 northbound; two lane changes required in, what, 1000 feet? I wouldn't be surprised if that movement is relocated back to something like its current path.

Next, check out the ramp from eastbound 285 to Ashford Dunwoody Road. It starts west of 400 and continues as two lanes until right before it joins the ramp from 400, at which point it narrows to only one lane. I guess that'll meter the flow into the DDI-- better for traffic to back up on that long ramp than to gridlock the DDI.

There will be no access via 285 or its CD roads between Roswell and Glenridge Roads, or between Peachtree Dunwoody and Ashford Dunwoody. No great loss there, I guess.

Now, back to that ramp from Ashford Dunwoody onto 285 westbound: The 285 mainline under Ashford Dunwoody is only four lanes in each direction, which makes sense because the terminals for the two-lane ramps serving 400 the the Dunwoodies are all well east of there. So far, so good. But the ramp from Ashford Dunwoody adds two more lanes. Only a short distance downstream, there's a single lane drop exit for Roswell Road, which means that eastbound 285 traffic bound for Roswell Road must change lanes twice in a short distance while battling traffic merging left to get on 285-- or staying put to get to Roswell Road. I wouldn't be surprised if the ramp from 285 westbound to Roswell Road ends up being widened to two lanes for its entire length to add an optional lane at the exit from 285 and thereby avoid imposing a double lane change, though that would make life a bit more difficult for 400 northbound to 285 westbound traffic-- unless the extra lane was terminated before the loop ramp from 400 joins the Roswell Road ramp. We'll see, I guess.

The fifth lane of 285 westbound? It just ends somewhere before the onramp from Glenridge.

I'd like to comment more on the 400 sector of the project, but the .pdf's GDOT has posted aren't current-- they don't match the ones for 285. 

[adventurernumber1]

How do you like this routing I made of a possible outer beltway in the Atlanta Metropolitan Area. It could be better, it's just like this since I'm zoomed out so far, but still. http://prntscr.com/4evlxf

Just forget about that, lol. This new routing I made is far better. So, how do you like this for an outer Atlanta Beltway: http://prntscr.com/4klfan

[adventurernumber1]

And the proposed beltway's only concurrency is with I-75 in Acworth, if you notice.

[Tom958]

And the proposed beltway's only concurrency is with I-75 in Acworth, if you notice.

This sort of thing belongs in Fictional Highways.

[afone]

http://www.bizjournals.com/atlanta/blog/capitol_vision/2014/09/shovel-turned-on-northwest-corridor-project.html

[afone]

http://www.bizjournals.com/atlanta/morning_call/2014/09/gwinnett-officials-approve-2-08m-for-new-i-85.html

[Tom958]

I had an errand to run this evening: from my jobsite at 285 and 75 (actually, very near the new Braves Stadium site) to Cartersville (near downtown) to pick up my new (to me-- it's a 2007) company van, then home to Lawrenceville. What follows is a mini trip report:

The guy who drove me up to Cartersville is maddeningly GPS dependent, and his GPS told him to exit I-75 at Red Top Mountain Road, exit 285. I've driven by there on 75 too many times to count and never thought anything of it: it's just a local road with a four lane dual bridge diamond interchange with 75 in case a whole clump of motels, gas stations and fast food places decided to pop up there. No big deal, right? So we get off of 75, turn left toward 41 and Cartersville, then... right again, though a single quadrant interchange with 41? And Red Top Mountain Road continues west across 41 on a rather high bridge. Wassup with that? Well, it seems that Red Top Mountain Road was recently extended to provide a bypass of Emerson. Check this out: https://www.google.com/maps/@34.1224332,-84.7765654,5412m/data=!3m1!1e3 . There's another single quadrant interchange with GA 293 (old US 41), which runs along the railroad. Then the new bypass ties into Old Alabama Road. Follow Old Alabama west, it faintly begs to be extended to GA 113. And a mile or so west of that hypothetical intersection, GA 113 was dualized-- some time ago, given the lack of current-style separated left turn lanes.

I suppose I should've known about this, but it's so nonsensical that I don't feel too bad about not knowing. 

After that, home to Lawrenceville. I could've taken the freeways, but it was sixish, and experience leaving my jobsite at sevenish has taught me that top end 285 is still so jammed at that hour that it's quicker to take 75 all the way to 85 and avoid 285 altogether. Between not wanting to do Cartersville-Lawrencevile via Midtown Atlanta and general roadgeeky curiousity, I decided to take GA 20 instead. As many of you know, there are numerous passing lanes on GA 20, and turn lanes that started out as passing lanes. Between I-75 and Canton, some new ones are being added. Unusually, though, there are several places where there are retaining walls topped with Jersey barriers right at the edge of the new roadway. In at least one place, they're actually on both sides of the road, with only three lanes or so worth of width between them 9I wish now that I'd taken a photo, but it snuck up on me. Maybe next time, lol.). Right-of-way doesn't look especially constrained there-- perhaps they did it to minimize stormwater runoff, since Lake Allatoona is nearby. Still, it seems odd that a section of highway that GDOT tried for years to replace with a freeway is being widened so conservatively, especially considering how much money was blown on the nearly-useless Emerson Bypass.

Not too much to say about the rest of the trip except for the remarkable lack of traffic. Yes, it was sluggish, but the only real congestion I encountered was in downtown Cumming, and that was for only a quarter mile or so. I usually bypass Cumming using Bethelview Road to 141 to McGinnis Ferry, but today I stuck to GA 20. However, in downtown Cumming I spotted what turned out to be Veterans Memorial Blvd, a promising-looking five lane road leading southward from downtown, so I took it, and it led me straight into GA 20. Why it isn't signed as GA 20 is a mystery to me.

Widening of the remaining two-lane section of GA 20 between GA 400/US 19 and Gwinnett County is finally underway, though the last sections have only been cleared and silt fenced so far.

[2Co5_14]

The guy who drove me up to Cartersville is maddeningly GPS dependent, and his GPS told him to exit I-75 at Red Top Mountain Road, exit 285. I've driven by there on 75 too many times to count and never thought anything of it: it's just a local road with a four lane dual bridge diamond interchange with 75 in case a whole clump of motels, gas stations and fast food places decided to pop up there. No big deal, right? So we get off of 75, turn left toward 41 and Cartersville, then... right again, though a single quadrant interchange with 41? And Red Top Mountain Road continues west across 41 on a rather high bridge. Wassup with that? Well, it seems that Red Top Mountain Road was recently extended to provide a bypass of Emerson. Check this out: https://www.google.com/maps/@34.1224332,-84.7765654,5412m/data=!3m1!1e3 . There's another single quadrant interchange with GA 293 (old US 41), which runs along the railroad. Then the new bypass ties into Old Alabama Road. Follow Old Alabama west, it faintly begs to be extended to GA 113. And a mile or so west of that hypothetical intersection, GA 113 was dualized-- some time ago, given the lack of current-style separated left turn lanes.

Still, it seems odd that a section of highway that GDOT tried for years to replace with a freeway is being widened so conservatively, especially considering how much money was blown on the nearly-useless Emerson Bypass.

The project actually isn't just a bypass of Emerson - it will actually serve as the new routing for GA-113 to bypass the much more congested downtown Cartersville.  It will be extended past the end of Old Alabama Rd to the existing GA-113.  There is a significant amount of truck traffic that currently uses the narrow 2-lane section of GA-113 through the residential and commercial section of Cartersville which will benefit from the bypass once it is completed.

[adventurernumber1]

The project actually isn't just a bypass of Emerson - it will actually serve as the new routing for GA-113 to bypass the much more congested downtown Cartersville.  It will be extended past the end of Old Alabama Rd to the existing GA-113.  There is a significant amount of truck traffic that currently uses the narrow 2-lane section of GA-113 through the residential and commercial section of Cartersville which will benefit from the bypass once it is completed.

I had no idea about that. That sounds like a pretty good idea! What will the old SR 113 become? Obviously it's current concurrency with SR 61 will become at least just SR 61, but what about the stretch near I-75, and the very short stretch in between where SR 61 cuts off south, and where Old Alabama Road meets it. Surely you might know, since you seem to have information about this, and you're also a DOT worker, apparently.

[Tom958]

Still seems like overkill to me, though that's hardly a rare thing in Georgia.

Amusingly, I looked at the area on my phone's map thingie this afternoon rush hour, and it showed congestion on Old Alabama where it corners into the bypass. The shortcut from I-75 through Emerson is still popular, it seems.

[Eth]

Does Anyone know when the variable speed limits are to take effect on IH 285. The signs have been set up on the Jersey barriers. Also, for some reason they are deciding to waste taxpayer money and replace the signage on certain parts of the Interstate (Lavista road, Lawrenceville HWY. Glenwood Dr, etc. The new signage has the larger fonts...

GDOT's website says they're switching on the new signs in September.

September has, of course, come and gone, and the signs haven't been switched on yet. Apparently it is now scheduled for this coming Sunday, October 5.

(FWIW, I can't actually find that exact date on the GDOT website; their page for the project just says "October".)

[Tom958]

Maybe this belongs in the Traffic Control forum...

Erected yesterday or today, just beyond this fine APL sign...



...is this. It's located right where the optional lane actually splits, i.e. is 24+ feet wide. So, instead one one big splitting arrow as on the previous sign, there are two big non-splitting ones. It extends the logic of using two black-on-yellow arrows to indicate one compulsory and one optional exit lanes, which I already freakin' hate. And I hate this, too, though I'd be OK with it if the optional lane arrow didn't have an exit only legend:



EDIT: Here's the previous scheme, which had issues of its own.

[Eth]

...is this. It's located right where the optional lane actually splits, i.e. is 24+ feet wide. So, instead one one big splitting arrow as on the previous sign, there are two big non-splitting ones. It extends the logic of using two black-on-yellow arrows to indicate one compulsory and one optional exit lanes, which I already freakin' hate. And I hate this, too, though I'd be OK with it if the optional lane arrow didn't have an exit only legend:

As far as I'm concerned, this is erroneous. From the driver's perspective, there are only five lanes here, unless we assume that the driver is looking directly up (i.e. at a 90-degree angle to the horizon) at the sign (though, given Atlanta drivers, I suppose we can't completely discount that possibility). Of course, if we use the split left-straight arrow here, the lane spacing becomes an issue since the option lane is indeed quite a bit wider than a typical lane at this point.

Is there any good reason why the gantry couldn't be moved a couple hundred feet upstream?

[Tom958]

As far as I'm concerned, this is erroneous. From the driver's perspective, there are only five lanes here, unless we assume that the driver is looking directly up (i.e. at a 90-degree angle to the horizon) at the sign (though, given Atlanta drivers, I suppose we can't completely discount that possibility). Of course, if we use the split left-straight arrow here, the lane spacing becomes an issue since the option lane is indeed quite a bit wider than a typical lane at this point.

Is there any good reason why the gantry couldn't be moved a couple hundred feet upstream?

Moving the assembly upstream would make it a repeat of the previous assembly, which...

To me, it's advisable to put an overhead sign right where the extra lane begins, as was done with the conventional signage that the new APL replaced. I find this APL to be far less objectionable than the usual sequence:





One complication here is that the APL is still desired to indicate a drop-plus-optional exit at 16th-14th-10th Streets a short distance further. Going to conventional signage at the site of this assembly would've prevented that. I'm sure that's why GDOT did what it did here.

(As an added, irrelevant complication, the 16th-14th-10th exit is depicted on the APL signs as two lanes with an optional lane, and I think the lanes are striped accordingly. However, the conventional signage at the exit point bears only one black-on-yellow down arrow, not two. Wassup with that?)

Bottom line, for me: The real issue is the latest MUTCD's insistence on labeling optional exit lanes as dropped lanes, as shown in the Wesley Chapel example above. If they'd go back to one white-one black arrow instead (upward-pointing, please!), and if there wasn't an incorrect EXIT ONLY legend on that post-split arrow on the new APL sign, I would consider this APL sign to be absolutely peacherific.

[mrsman]

A good fix for the sign above maybe to use "Toronto" style APL.  (i.e. just having arrow and option arrow for the exit without showing arrows for the thru route.)

In this way you have an APL sign for the 14th Street exit, a green sign in the middle with no arrows saying "75/85 Atlanta" and conventional exit arrows for the exit to I-85 north.

So we're basically signing for the left exit and the right exit and no saying much at all (lane-wise) with respect to the thru lanes.

Besides, the earlier BGS had clearly laid out the pattern, is this sign even necessary over here?

[Tom958]

Besides, the earlier BGS had clearly laid out the pattern, is this sign even necessary over here?

No, but then neither are many of the other APL signs that GDOT has been installing, the ones upstream from here being an exception.

There's another new rogue APL sign (no optional lane) on 285 wesbound approaching 75 on the north side. Now that exit sports conventional, one-big-splitting-arrow directional and APL signage. 

[Eth]

I drove the northeast quadrant of I-285 this morning from US 78 to GA 400, and I can confirm that the new variable speed limit signs are now in operation. Well, okay, about two-thirds of them are. With free-flowing traffic as is normal for a Sunday morning, all the signs that were on reflected the new maximum limit of 65 (though some of the old SPEED LIMIT 55 signs remain in place).

[Tom958]

i'll just blurt it out: Variable speed limit signs are about the most uninteresting road-related item I can imagine. i'm currently commuting via top end 285, but I'll be astonished if they have any detectable effect on my life. Except...

This morning I was almost thirty minutes late to work, even though I left only ten minutes past my target time, and traffic seemed pretty decent. Must've been those damned signs. 

Trooper that i am, though, I'll give a report on what i saw: the signs were set to 35 in the congested section between 85 and Ashford Dunwoody, 55 from there to 400 (one pair of signs only) as traffic freed up, and 65 over to 75, which was free flow at the time.

[Eth]

i'll just blurt it out: Variable speed limit signs are about the most uninteresting road-related item I can imagine. i'm currently commuting via top end 285, but I'll be astonished if they have any detectable effect on my life. Except...

Haha, fair enough. Really they're only interesting to me because they've never been used in the state of Georgia before. My excursion yesterday wasn't even for the purpose of checking them out; I just happened to be going somewhere that required the use of that part of 285. Considering the only part I use with any regularity is the short segment between US 278 and I-20 on the east side, I wouldn't expect to see much effect either (especially in the morning traveling southbound).

[WashuOtaku]

I drove the northeast quadrant of I-285 this morning from US 78 to GA 400, and I can confirm that the new variable speed limit signs are now in operation. Well, okay, about two-thirds of them are. With free-flowing traffic as is normal for a Sunday morning, all the signs that were on reflected the new maximum limit of 65 (though some of the old SPEED LIMIT 55 signs remain in place).

Weren't the speed limit signs on I-285 just suggestions anyway?  Every time I get on I-285, I have to put on my racing gloves. 

[Tom958]

Weren't the speed limit signs on I-285 just suggestions anyway?  Every time I get on I-285, I have to put on my racing gloves. 

Not in my experience. People speed given the opportunity, of course, but it's not crazy.

Having mentioned that, I'm commuting there early enough to arrive at work before seven, just when congestion is starting to bite. And, guess what: with cars speeding up and slowing down erratically and changing lanes to jockey for position, I have better things to keep my eye on than the speedometer. For me, the new variable limits will indeed by just a suggestion.

This morning I saw a sign change from 45 to 35. It was dark for several seconds between. 35, IIRC, is the speed associated with LOS E-- I wonder if they ever go lower than that.

[afone]

Work begins on Windy Hill improvements
http://www.bizjournals.com/atlanta/blog/capitol_vision/2014/10/work-begins-on-windy-hill-improvements.html

[Tom958]

There are cranes belonging to the Northwest Corridor joint venture contractor onsite at the 75-285 interchange, too, apparently starting on the flyovers there. That's about to become a busy part of town.