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Higher Speed Limits Considered in near Dallas Freeways

Started by dfwtbear, August 08, 2013, 11:36:56 AM

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Road Hog

Realistically, the only time you could do 70 on US 75 between Dallas and McKinney is in the wee hours of the morning because traffic is really heavy at almost all hours and there is also construction.


dfwmapper

The speed studies only count free-flow traffic. If there is a line of cars being held up by someone going really slow, only that very first car counts. If the road is fully congested like at rush hour, none of them count. The speed limit through Collin County has not yet changed, and won't until construction is complete.

wxfree

Quote from: dfwmapper on July 26, 2015, 12:46:34 AM
I went for a drive today, and noticed that I-635 is now posted at 65 between PGBT and SH 121. Given how wide open that part of LBJ is and how fast everyone drives, I would have expected it to be 70, but apparently not.

That section of LBJ confused me.  Looking at all of the data, it seems that its control section number was changed since 2001.  Part of 2374-1 had an environmental speed limit cancelled, and also had a new speed limit of 70 established.  But these are two different 2374-1s.  The far east end was apparently that number before, and is now 2374-7.  It had an environmental speed limit of 60, which was cancelled and no new limit was established, so it went back to what it was before, 65.  The new 2374-1 is about from I-35E to SH 78 and part of that stretch is where the new limit of 70 was established.  The cancellation doesn't affect that part of the road because it didn't have an environmental speed limit (it had been at 60 all along).  The real kicker is that both the cancelled limit on the east end of the highway and the new speed limits that end near US 75 have the exact same ending mile point, 9.108.

I've gone over every TxDOT speed limit minute order that's online, back to 2005, and I've seen how sometimes they make no sense.  My favorite is when it's 14.708 miles from mile point 10.000 to mile point 37.247.  I can only wonder how that happened and where exactly the gap is.  But this is the biggest challenge they've given me.  I know of no other control sections that were renumbered.

I'll change my map to add the 65s in that area.
I'd like to buy a vowel, Alex.  What is E?

Aren Cambre

Quote from: dfwmapper on July 26, 2015, 11:54:11 AM
The speed studies only count free-flow traffic. If there is a line of cars being held up by someone going really slow, only that very first car counts. If the road is fully congested like at rush hour, none of them count. The speed limit through Collin County has not yet changed, and won't until construction is complete.
Through all of Collin, or just in Plano?

dfwmapper

Last time I went through (mid-May), it was still 60 through Plano and 65 from the Plano/Allen line to the Collin/Grayson county line, just as it has been. The construction in Plano and Allen lasts until early 2017. SRT to US 380 is supposed to be done in early 2016, US 380 to south of SH 121 next month, and from there north to the current end is supposed to be done in about a year. From the end of the current construction through the FM 455 interchange is supposed to be let in December, and from that to the Grayson line will follow, so who knows when everything will be done. I might be making a trip up to Oklahoma this week so I'll confirm that they haven't change anything yet.

wxfree

There is another increase on the minute order this month, on US 80.  The speed limit was already raised to 70 in Kaufman County.  This month they'll be raising the speed limit to 65 for about the first 2 miles after the split from I-30, and then 70 from there.

These increases are above the pre-ESL levels.  In 2001, the speed limit was 60 until I-635, 65 until Forney, and 70 east of there.  After this change, the speed limit will be 70 until about 2 miles before I-30, and 65 for the western end.
I'd like to buy a vowel, Alex.  What is E?

dfwmapper

I made the Oklahoma trip today. Confirmed the speed limits on US 75 are as they have been. 60 through Plano, 65 from Plano/Allen line to Collin/Grayson line, 75 through Grayson except for the construction zone north of Howe and the substandard part in Sherman.

wxfree

They're still working at this, gradually adding more increases.  I've updated the map to show the latest changes, including this month's minute order.

I-820 from the southern interchange with SH 121 south to I-20, 60 up to 65
US 77 south from Milford a short distance to the Hill County line, 65 up to 70
US 287 bypass around Waxahachie, 65 up to 70
SH 5 north from Anna a short distance to the Grayson County line, 65 up to 70
SH 78 from north of Blue Ridge to north of Farmersville, 65 up to 70
SH 121 from north of Melissa to Fannin County line, 65 up to 70
US 80 from east of Terrell to Van Zandt County line, 65 up to 70
Also, the 65 zone on SH 360 north of I-30 has been extended to the north end of the highway at SH 121
I'd like to buy a vowel, Alex.  What is E?

wxfree

It appears that the speed limit along the western 9 miles of US 380 in Denton County will increase to 70.  In 2011 the environmental speed limit of 65 was cancelled and replaced with permanent speed limit of 65.  There was no change in number, but there was a change in status from a temporary speed limit reduced for environmental purposes to a permanent speed limit based on regular engineering.  The road has been upgraded from two-lane to a divided road.  The 2011 speed limit was cancelled last month.  No new limit was established, which I think means that there is no regulatory speed limit so the state default of 70 takes effect.
I'd like to buy a vowel, Alex.  What is E?

wxfree

Due to personal curiosity, I wanted to see how the current speed limits compare with those of the late 90s, the post-55 and pre-ESL era.  A lot of the city freeways have higher speed limits now.  Most of the non-freeway roads have lower limits, either due to the 5 mph reduction being retained, or due to bigger reductions over the years for other reasons.  SHs 78 and 121 in northeastern Collin County and SH 171 in Parker County are the only two-lane highways (other than a couple of short pieces next to county lines) on which the original 70 mph speed limits were restored.

The increases on SH 121 between I-35W and I-820 and on SH 161 were implemented after those roads didn't get environmental speed limits and TxDOT later decided on the increases.  Those changes are not mapped, because they were "organic" changes unaffected by the ESL policy.  NTTA changes are not mapped (because I don't know them).

Green lines show reductions of 5 mph.  Black lines show reductions of 10 mph.  Some bigger reductions due to expansion of urban areas were not mapped.  Yellow diamonds show increases of 5 mph.  Red diamonds show increases of 10 mph.  The green circles along I-35W are where the speed limit was 55 (now 50 due to the work zone) and has been ordered increased to 70 when the work is complete, for an increase of 15 mph.  Places with no changes are not marked.  Managed lanes are not included.

Two small areas are somewhat confusing.  On the west end of US 80, there's a short unmapped increase from 60 to 65, and the mapped changes show an increase from 60 to 70 and east of I-635 an increase of 65 to 70.  Also, on US 175 the westernmost change is from 60 to 65, the red zone from about Loop 12 to I-20 is an increase from 60 to 70, and the yellow zone southeast is for 65 to 70.  Southeast from there, the speed limit was 70 before.

http://www.patternsandprinciples.com/otherfiles/rs/eslcomps.jpg
I'd like to buy a vowel, Alex.  What is E?

Aren Cambre

Quote from: wxfree on April 24, 2016, 02:11:05 AMThe increases on SH 121 between I-35W and I-820 and on SH 161 were implemented after those roads didn't get environmental speed limits and TxDOT later decided on the increases.  Those changes are not mapped, because they were "organic" changes unaffected by the ESL policy.  NTTA changes are not mapped (because I don't know them).
The SH 121 speed limit change to 65 MPH was done years ago, possibly more than 10 years ago. You are right that it was not subject to ESLs because it had a 60 mph speed limit before the silly ESL scheme started.

wxfree

I've updated both maps to reflect this month's minute order, which raises the speed limit to 70 on I-635 as far west as I-35E, which is an increase of 10 mph above the old limit.  On I-635, the speed limit will be 70 from I-20 to I-35E, and then 65 to the Tarrant County line.  The Tarrant County portion is so short that no signs are posted, so the limit is effectively the same, although it's technically supposed to be 60.
I'd like to buy a vowel, Alex.  What is E?

Aren Cambre

Quote from: wxfree on April 25, 2016, 04:01:11 PM
I've updated both maps to reflect this month's minute order, which raises the speed limit to 70 on I-635 as far west as I-35E, which is an increase of 10 mph above the old limit.  On I-635, the speed limit will be 70 from I-20 to I-35E, and then 65 to the Tarrant County line.  The Tarrant County portion is so short that no signs are posted, so the limit is effectively the same, although it's technically supposed to be 60.
Glad they are doing that! Back in 2010, I met some civil engineers working on the I-635 redo project, and they said it has a 65 mph design speed. My personal experience with that road reinforces that design speed is just a laboratory measurement that should not control the speed limit. Now if they could just jack the tolled lanes to 85 mph... ;-)

Chris

The express toll lanes of I-635 are now posted at 75 mph. I wonder if this is the highest urban speed limit in the United States?


Aren Cambre

Quote from: Chris on April 28, 2016, 02:27:21 PM
The express toll lanes of I-635 are now posted at 75 mph. I wonder if this is the highest urban speed limit in the United States?


I hope you're OK that I totes stole this and posted it on Facebook. :-)

dfwmapper

Quote from: Chris on April 28, 2016, 02:27:21 PM
The express toll lanes of I-635 are now posted at 75 mph. I wonder if this is the highest urban speed limit in the United States?
That depends on how you define "urban". SH 130 through Pflugerville has an 80mph limit. The LBJ TEXpress lanes weren't anywhere close to the first 75mph in Texas either. The I-820/SH 183/SH 121 TEXpress lanes were first in the DFW area, and the SH 45, 183A, and 290 toll roads in the Austin area had 75mph limits long before anything up here did.

wxfree

They're still going.  This month includes a speed limit increase to 65 on I-345 between SS 366 and I-30 (the whole length of it).  The speed limit will be higher in the adjoining part of the downtown freeway loop than it is along the forested stretch of I-45 to the south.  Someone along I-45 in Dallas County must have really wanted low speed limits in order to end up with the disparities with I-635 and US 75, and now this one.
I'd like to buy a vowel, Alex.  What is E?

Aren Cambre

Quote from: wxfree on June 27, 2016, 07:20:55 PM
They're still going.  This month includes a speed limit increase to 65 on I-345 between SS 366 and I-30 (the whole length of it).  The speed limit will be higher in the adjoining part of the downtown freeway loop than it is along the forested stretch of I-45 to the south.  Someone along I-45 in Dallas County must have really wanted low speed limits in order to end up with the disparities with I-635 and US 75, and now this one.
Can you clarify? I-345 and I-45 in Dallas were signed at 65 MPH many months ago.

wxfree

Quote from: Aren Cambre on July 05, 2016, 11:51:31 PM
Quote from: wxfree on June 27, 2016, 07:20:55 PM
They're still going.  This month includes a speed limit increase to 65 on I-345 between SS 366 and I-30 (the whole length of it).  The speed limit will be higher in the adjoining part of the downtown freeway loop than it is along the forested stretch of I-45 to the south.  Someone along I-45 in Dallas County must have really wanted low speed limits in order to end up with the disparities with I-635 and US 75, and now this one.
Can you clarify? I-345 and I-45 in Dallas were signed at 65 MPH many months ago.

Last month's minute order included a speed limit of 65 on the full length of I-345.  I check the orders every month and had not seen one establishing that speed on that road.  If the signs had already been changed, I can only guess that it was under the authority of a Dallas city ordinance, and that TxDOT is just now catching up in its minutes.  Cities have concurrent jurisdiction with TxDOT over speed limits.  I don't recall seeing any speed limit signs the last time I was there, a few months ago.
I'd like to buy a vowel, Alex.  What is E?

dfwmapper

Southbound the last speed limit sign on US 75 is just before the ramp to Woodall Rodgers, and it's 70mph. The next speed limit sign, and the only one I-345, is right where the Main/Commerce ramp merges on, about 600' north of the center line of I-30 and that went from 60 to 65 between March and April 2015 based on the streetview history (https://goo.gl/maps/gknS1CS8e4s). Northbound the last sign is at the DART maintenance yard crossing just north of the US 175 merge (https://goo.gl/maps/JwtGHqtda6t), nothing on I-345, and the first one on US 75 is 70mph between the merge from Woodall Rodgers and the Haskell exit (https://goo.gl/maps/rKJiYhPbPe22). Whatever the limit was set as by the TTC before, it was never reflected via signage in the field. Also, the entire length of I-45 in Dallas County has been 65 for over a year, IIRC in the initial batch of changes, the same time it went to 70 in Ellis.

wxfree

Quote from: dfwmapper on July 06, 2016, 01:26:19 AM
Southbound the last speed limit sign on US 75 is just before the ramp to Woodall Rodgers, and it's 70mph. The next speed limit sign, and the only one I-345, is right where the Main/Commerce ramp merges on, about 600' north of the center line of I-30 and that went from 60 to 65 between March and April 2015 based on the streetview history (https://goo.gl/maps/gknS1CS8e4s). Northbound the last sign is at the DART maintenance yard crossing just north of the US 175 merge (https://goo.gl/maps/JwtGHqtda6t), nothing on I-345, and the first one on US 75 is 70mph between the merge from Woodall Rodgers and the Haskell exit (https://goo.gl/maps/rKJiYhPbPe22). Whatever the limit was set as by the TTC before, it was never reflected via signage in the field. Also, the entire length of I-45 in Dallas County has been 65 for over a year, IIRC in the initial batch of changes, the same time it went to 70 in Ellis.

These are changes I was not aware of, and did not see in the minute orders.  TxDOT's policy is to coordinate with cities.  It seems Dallas made changes that were not reflected in the minute orders.  I'll have to change my map to reflect those changes.
I'd like to buy a vowel, Alex.  What is E?

Aren Cambre

Quote from: wxfree on July 06, 2016, 02:03:00 AMThese are changes I was not aware of, and did not see in the minute orders.  TxDOT's policy is to coordinate with cities.  It seems Dallas made changes that were not reflected in the minute orders.  I'll have to change my map to reflect those changes.
I'll bet you major $$$ that Dallas had nothing to do with it. Dallas's traffic engineering department is a joke, disregarding MUTCD and commonly-accepted engineering practices and routinely committing malparactice to frustrate and annoy drivers, such as unwarranted stop signs and lower speed limits. I think Dallas mentally got out of setting freeway speed limits when its arbitrary limits were overruled in the mid-'90s. See http://people.smu.edu/acambre/traffic2003/dallasSpeedLimitFaxes.asp.

dfwmapper

Quote from: wxfree on July 06, 2016, 02:03:00 AM
These are changes I was not aware of, and did not see in the minute orders.  TxDOT's policy is to coordinate with cities.  It seems Dallas made changes that were not reflected in the minute orders.  I'll have to change my map to reflect those changes.
Is it possible that this is just another one of those oddities with the control sections like you came across with LBJ? Or a reversion to the old limits that was never updated via MO?

wxfree

Quote from: dfwmapper on July 09, 2016, 11:36:46 PM
Quote from: wxfree on July 06, 2016, 02:03:00 AM
These are changes I was not aware of, and did not see in the minute orders.  TxDOT's policy is to coordinate with cities.  It seems Dallas made changes that were not reflected in the minute orders.  I'll have to change my map to reflect those changes.
Is it possible that this is just another one of those oddities with the control sections like you came across with LBJ? Or a reversion to the old limits that was never updated via MO?

Other than the LBJ confusion, I've never seen an apparently renumbered control section.  I've seen other oddities since I started paying attention during the statewide speed increase, but never another example of that.  In the minute order, the change along I-45 in Dallas County was along only 9 miles, so changes in control section numbers couldn't account for the difference in length.  The minute orders include cancelled speed zones.  The Transportation Code says that TTC may change speed limits "by order recorded in its minutes" so that appears to mean that there aren't changes by TxDOT without minute orders.  I've seen oddities over the years, variances from the minute order, that I can't explain.  This may be one of those.  My first guess would be that the change was based on a city ordinance, since the entire affected section is in Dallas, but a search of the city council records doesn't reveal an ordinance.  For now, it's a mystery.
I'd like to buy a vowel, Alex.  What is E?

dfwmapper

In going back and looking through it some more, the original environmental speed limits and the cancellations of them only applied from the loop (I-20/I-635/SH 121/I-820) outwards, so they never would have applied to the northern section of I-45 to begin with. I did do a search to see if I could find any references to that control section in the MOs, and there weren't any, so I'm as stumped as you. The only thing I can think of is that maybe that portion was never legally changed to 60 to begin with, and posting back as 65 was just correcting that earlier error?



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