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National Boards => General Highway Talk => Topic started by: webny99 on January 06, 2019, 06:42:20 PM

Title: Different Direction, Different Speed Limit
Post by: webny99 on January 06, 2019, 06:42:20 PM
What are some examples of different directions of traffic on the same road having a different speed limit?

I don't mean minor discrepancies of a few feet, I mean explicitly different limits over the course of a mile or more. For example, I-190 approaching the Canadian border has a northbound limit of 45 mph and a southbound limit of 65 mph --- a 20 mph differential for about 2 miles!
Any other roads like this with significantly different limits depending on the direction?
Title: Re: Different Direction, Different Speed Limit
Post by: hbelkins on January 06, 2019, 07:25:05 PM
Quote from: webny99 on January 06, 2019, 06:42:20 PM
What are some examples of different directions of traffic on the same road having a different speed limit?

I don't mean minor discrepancies of a few feet, I mean explicitly different limits over the course of a mile or more. For example, I-190 approaching the Canadian border has a northbound limit of 45 mph and a southbound limit of 65 mph --- a 20 mph differential for about 2 miles!
Any other roads like this with significantly different limits depending on the direction?

Isn't there a stretch of I-79 in Pennsylvania like this between I-70 and the West Virginia border?
Title: Re: Different Direction, Different Speed Limit
Post by: signalman on January 06, 2019, 07:26:37 PM
I assume you searched for this topic prior to starting this thread because this topic sounds familiar.  I seem to recall it being discussed at one point in the past.  There may not be a specific thread out there about it, it very well could have came up in the course of conversation on another topic.  Not that threads ever derail.
Title: Re: Different Direction, Different Speed Limit
Post by: vdeane on January 06, 2019, 09:24:00 PM
Quote from: webny99 on January 06, 2019, 06:42:20 PM
What are some examples of different directions of traffic on the same road having a different speed limit?

I don't mean minor discrepancies of a few feet, I mean explicitly different limits over the course of a mile or more. For example, I-190 approaching the Canadian border has a northbound limit of 45 mph and a southbound limit of 65 mph --- a 20 mph differential for about 2 miles!
Any other roads like this with significantly different limits depending on the direction?
Region 7 loves this.  It happens on I-81 northbound approaching the Thousand Islands Bridge (40/55) and Canada (40/65) and both directions of I-781 approaching each terminus (45/65).  Sad to see that it's spreading.

In Region 1, it also happens on Fuller Road Alternate (that little connector between I-87 and US 20 - it's 45 southbound and 55 northbound) and on I-87 at exit 8 (55/65).
Title: Re: Different Direction, Different Speed Limit
Post by: 1995hoo on January 07, 2019, 09:03:56 AM
I don't know if it's still like this, but in 1997 the Alabama DOT lowered the speed limit on southbound I-65 beginning a mile or two north of Montgomery to either 60 or 65 while leaving the northbound speed limit at 70. There had been accidents involving southbound traffic and they wanted people to slow down before crossing the river.




Quote from: signalman on January 06, 2019, 07:26:37 PM
I assume you searched for this topic prior to starting this thread because this topic sounds familiar.  I seem to recall it being discussed at one point in the past.  There may not be a specific thread out there about it, it very well could have came up in the course of conversation on another topic.  Not that threads ever derail.

hbelkins raised the question as part of another thread in 2015. I was able to find it because I remembered citing the Montgomery example in a prior thread:

https://www.aaroads.com/forum/index.php?topic=16989.msg2111934#msg2111934
Title: Re: Different Direction, Different Speed Limit
Post by: bzakharin on January 07, 2019, 05:28:36 PM
The only real posted one I know is in Pittsgrove, NJ on Parvins Mill Road (CR 645) between Running Deer Trail and Garden Rd (CR 674) where Northbound the Speed Limit is 50, while Southbound it's 40. What the reasoning is I don't know, but if you look at this: https://www.google.com/maps/@39.5299461,-75.1114925,3a,37.5y,269.71h,87.11t/data=!3m6!1e1!3m4!1s-RTXDmAdofWfQAVCdd2_rg!2e0!7i13312!8i6656!5m1!1e1 the 4 on the sign is a patch over what probably used to be a 5, so it was probably 50 in both directions at some point.
Title: Re: Different Direction, Different Speed Limit
Post by: US 89 on January 07, 2019, 05:53:51 PM
The one that's always bothered me is on US 89 where it splits and runs on either side of I-15 between Salt Lake City and North Salt Lake, Utah.

The southbound direction has always been posted at 55 mph. The northbound side had been posted at 55, until the sign disappeared in around 2013. It was replaced in late 2015 with a 50 limit sign, with a strange "US 89" yellow plate that I've never seen anywhere else:

https://goo.gl/maps/LdRtbg5UwF62
Title: Re: Different Direction, Different Speed Limit
Post by: cl94 on January 07, 2019, 06:55:59 PM
NJ 15 in Jefferson. NB is 55 the entire way, SB goes down to 40. This is because SB uses the original 2-lane road through the area, while NB bypasses everything.
Title: Re: Different Direction, Different Speed Limit
Post by: signalman on January 07, 2019, 08:55:54 PM
NJ 23 in Kinnelon/West Milford.  Similar situation to the NJ 15 example cl94 cited.  NB utilizes the original 2 lane NJ 23, which is posted at 40 and is graded incorrectly for NB only traffic.  While the newer and better engineered SB is posted at 55.


BTW Josh, you're welcome for me bringing up 15 in chat  :-P
Title: Re: Different Direction, Different Speed Limit
Post by: roadman65 on January 07, 2019, 11:57:31 PM
In Watchung Reservation in Scotch Plains, NJ there was a part of Sky Top Drive that had 25 mph in one direction and 35 the other.

In Pine Castle, FL you have SR 527 where NB is 40 mph and SB is 35 mph, though one could argue that they are on a one way couplet.  I am not sure if the OP considers that fact or not, but given where both NJ 15 and NJ 23 in North Jersey are two separate carriageways in a rural area and farther apart than both Orange and Hansel Avenues in Pine Castle you might as well consider them to be one street.
Title: Re: Different Direction, Different Speed Limit
Post by: jakeroot on January 08, 2019, 12:51:12 AM
Similar to above: northbound I-5 slows down quite a bit prior to the Canadian Border. 70 > 35 (~a mile out) > 25 (~.6 miles prior to border).

Thanks to a signal and the backups it creates, westbound WA-512 in Tacoma slows from 60 > 45 about mile east of I-5...eastbound is 60 straight away.

A very annoying one in Olympia: eastbound 101 slows down from 60 > 45 about a mile west of I-5, despite the interchange being freeway-to-freeway. Westbound is 60 from I-5. Yes, the limit is ignored.

WA-16 has had several different limits over the last several years. Eastbound, going towards I-5, it used to go 60 > 55 (~2 miles out) > 40 (~1 mile out). Westbound (starting from I-5) it was 50 > 60 (~1 mile west of I-5). Apparently this was due to construction and the congestion it created. It has now been changed to 60 > 50 for eastbound, and 60 completely for westbound.
Title: Re: Different Direction, Different Speed Limit
Post by: pdx-wanderer on January 08, 2019, 12:39:37 PM
The only Oregon instance of this I can think of is I-5 in the mountainous area north of Grants Pass which has a short  stretch where the southbound speed limit is reduced to 55 mph, followed by a curve with a 45 mph advisory speed. Northbound there is no such configuration as the speed limit stays at 65 with a 55 mph advisory speed.
Title: Re: Different Direction, Different Speed Limit
Post by: ftballfan on January 08, 2019, 02:13:55 PM
60th St on the Kentwood/Gaines Twp boundary near Grand Rapids, MI is 45 eastbound and 55 westbound for a short stretch
Title: Re: Different Direction, Different Speed Limit
Post by: wxfree on January 09, 2019, 03:36:52 PM
US 62/180 near the Guadalupe Mountains in Texas has a speed limit of 75 going eastbound from SH 54 to near Guadalupe Pass, about 7 miles.  Going that direction is uphill.  Westbound, going downhill, the limit is 65.  There's about a 1,300 foot decrease in elevation.  None of it is really steep, but part of it near the top has about a 7 percent grade is somewhat curvy, with one advisory speed of 50.  For years, after the 2001 increase from 70 to 75, the speed limit was 75 in both directions.  I don't see a minute order reducing the speed limit, but the sign showing when it increases from 65 to 75 is gone, which has the effect of keeping the limit at 65 until the next sign after SH 54.  It's been 4 years since I've been there, and there's only slightly newer Street View, so the sign may be back, but it was gone for years before my last visit.
Title: Re: Different Direction, Different Speed Limit
Post by: Bickendan on January 10, 2019, 05:24:16 AM
Quote from: pdx-wanderer on January 08, 2019, 12:39:37 PM
The only Oregon instance of this I can think of is I-5 in the mountainous area north of Grants Pass which has a short  stretch where the southbound speed limit is reduced to 55 mph, followed by a curve with a 45 mph advisory speed. Northbound there is no such configuration as the speed limit stays at 65 with a 55 mph advisory speed.
The southbound lanes are a bit tighter through Myrtle Creek.
I imagine the eastbound lanes are a bit lower on 84/30 going up Emigrant [Cabbage] Hill, but it's been years since I've been through there.
Title: Re: Different Direction, Different Speed Limit
Post by: doorknob60 on January 10, 2019, 03:48:55 PM
Quote from: Bickendan on January 10, 2019, 05:24:16 AM
Quote from: pdx-wanderer on January 08, 2019, 12:39:37 PM
The only Oregon instance of this I can think of is I-5 in the mountainous area north of Grants Pass which has a short  stretch where the southbound speed limit is reduced to 55 mph, followed by a curve with a 45 mph advisory speed. Northbound there is no such configuration as the speed limit stays at 65 with a 55 mph advisory speed.
The southbound lanes are a bit tighter through Myrtle Creek.
I imagine the eastbound lanes are a bit lower on 84/30 going up Emigrant [Cabbage] Hill, but it's been years since I've been through there.

Actually, I-84 is 70 MPH both ways, just like the entire highway from the Idaho state line to The Dalles*. Should it be? Maybe not...but it is what it is.

*(exception of the variable speed section between La Grande and Baker City, but that defaults to 70 and usually is there)
Title: Re: Different Direction, Different Speed Limit
Post by: pdx-wanderer on January 12, 2019, 12:14:54 AM
Quote from: doorknob60 on January 10, 2019, 03:48:55 PM
Quote from: Bickendan on January 10, 2019, 05:24:16 AM
Quote from: pdx-wanderer on January 08, 2019, 12:39:37 PM
The only Oregon instance of this I can think of is I-5 in the mountainous area north of Grants Pass which has a short  stretch where the southbound speed limit is reduced to 55 mph, followed by a curve with a 45 mph advisory speed. Northbound there is no such configuration as the speed limit stays at 65 with a 55 mph advisory speed.
The southbound lanes are a bit tighter through Myrtle Creek.
I imagine the eastbound lanes are a bit lower on 84/30 going up Emigrant [Cabbage] Hill, but it's been years since I've been through there.

Actually, I-84 is 70 MPH both ways, just like the entire highway from the Idaho state line to The Dalles*. Should it be? Maybe not...but it is what it is.

*(exception of the variable speed section between La Grande and Baker City, but that defaults to 70 and usually is there)

I love that Cabbage Hill and the Blues have a higher speed limit than the Willamette Valley.
With its propensity for poor weather and nasty accidents, that whole section would be a good spot for the next round of variable speed limits. Definitely more useful than the ones around Portland that flash "slow" in stop and go traffic.
Title: Re: Different Direction, Different Speed Limit
Post by: Bitmapped on January 12, 2019, 10:09:19 AM
Quote from: hbelkins on January 06, 2019, 07:25:05 PM
Quote from: webny99 on January 06, 2019, 06:42:20 PM
What are some examples of different directions of traffic on the same road having a different speed limit?

I don't mean minor discrepancies of a few feet, I mean explicitly different limits over the course of a mile or more. For example, I-190 approaching the Canadian border has a northbound limit of 45 mph and a southbound limit of 65 mph --- a 20 mph differential for about 2 miles!
Any other roads like this with significantly different limits depending on the direction?

Isn't there a stretch of I-79 in Pennsylvania like this between I-70 and the West Virginia border?

Two places actually. I-79 northbound has a 55mph speed limit for about 1.5-mile just south of Exit #19 (PA 221/Ruff Creek) because of a 50mph curve; southbound is 70mph here.

Historically, I-79 northbound had a 40mph speed limit from a bit south of Exit #33 (US 40/Laboratory) to I-70 while the speed limit southbound was 55mph and 65mph. Now, northbound has a 55mph speed limit from about MM 31 to I-70 while southbound is 55mph between I-70 and US 40 and then 70mph south of there.

In West Virginia, I-70 eastbound goes to 65mph after US 40 Exit #5 while I-70 westbound drops to 55mph at Middle Wheeling Creek, giving a roughly mile long section with different speed limits.
Title: Re: Different Direction, Different Speed Limit
Post by: michravera on January 12, 2019, 06:34:52 PM
Quote from: webny99 on January 06, 2019, 06:42:20 PM
What are some examples of different directions of traffic on the same road having a different speed limit?

I don't mean minor discrepancies of a few feet, I mean explicitly different limits over the course of a mile or more. For example, I-190 approaching the Canadian border has a northbound limit of 45 mph and a southbound limit of 65 mph --- a 20 mph differential for about 2 miles!
Any other roads like this with significantly different limits depending on the direction?

Plenty of grades in California where the downhill speed limit for trucks is 35 MPH and the uphill is 55 MPH. It is actually against CalTrans policy to sign any such differences for LESS that a mile. There will also be frequent instances (especially in Nevada and Texas) where the speed limit is on a gradual reduction coming into town, but goes straight up to 55+ MPH in one step going out of town. Nevada also often drops a speed limit on the way to a junction or in advance of a stop sign but the speed limit is all of the way up to the road's design speed in the other direction. I know that I have seen this on US-6 in Western Nevada.
Title: Re: Different Direction, Different Speed Limit
Post by: sprjus4 on January 12, 2019, 08:43:43 PM
Quote from: michravera on January 12, 2019, 06:34:52 PM
Quote from: webny99 on January 06, 2019, 06:42:20 PM
What are some examples of different directions of traffic on the same road having a different speed limit?

I don't mean minor discrepancies of a few feet, I mean explicitly different limits over the course of a mile or more. For example, I-190 approaching the Canadian border has a northbound limit of 45 mph and a southbound limit of 65 mph --- a 20 mph differential for about 2 miles!
Any other roads like this with significantly different limits depending on the direction?

Plenty of grades in California where the downhill speed limit for trucks is 35 MPH and the uphill is 55 MPH. It is actually against CalTrans policy to sign any such differences for LESS that a mile. There will also be frequent instances (especially in Nevada and Texas) where the speed limit is on a gradual reduction coming into town, but goes straight up to 55+ MPH in one step going out of town. Nevada also often drops a speed limit on the way to a junction or in advance of a stop sign but the speed limit is all of the way up to the road's design speed in the other direction. I known that I have seen this on US-6 in Western Nevada.
I've seen in Texas frequently (on two or four lane) where it will gradually slow down for the town, but outbound it goes from the town speed limit to 55 MPH to 75 MPH. I wonder if it's ever jumped straight to 75 from 35 - 40.

Stops in Texas are basic. Speed limit 75 - four-way stop ahead - Stop - go - speed limit 75. Simple. I love it. One of my favorite states to drive in.
Title: Re: Different Direction, Different Speed Limit
Post by: TheHighwayMan3561 on January 12, 2019, 09:09:33 PM
MnDOT seems to go to great lengths to avoid this kind of thing. Not sure if that's a state law or just their policy.

I-394, between 94 and downtown: posted 40 both directions, even though westbound can probably be 50-55 heading away from downtown.

MN 61 expressway: northbound leaving Duluth, posted speed 40 across the railroad tracks to match where the 65 zone ends southbound. Ditto in Two Harbors, where the expressway southbound is forced to stay 55 until after Lake County Road 9 where it goes to 65, again matching the location of the 65-55 drop going northbound.

One example that does defy this though is I-35W in Bloomington, which goes to 55 northbound at 86th St while southbound goes to 65 at 82nd St, if not just past 494.
Title: Re: Different Direction, Different Speed Limit
Post by: wxfree on January 14, 2019, 01:08:58 AM
Quote from: sprjus4 on January 12, 2019, 08:43:43 PM
I've seen in Texas frequently (on two or four lane) where it will gradually slow down for the town, but outbound it goes from the town speed limit to 55 MPH to 75 MPH. I wonder if it's ever jumped straight to 75 from 35 - 40.

Stops in Texas are basic. Speed limit 75 - four-way stop ahead - Stop - go - speed limit 75. Simple. I love it. One of my favorite states to drive in.

The speed zone manual specifies that speed limits should not change by more than 15 mph, and that a change should not occur less that 0.2 mile from the previous change.  This rule is not always followed.  I know of a place where the limit drops from 50 to 30, and several where it increases from 55 to 75.  At the latter locations, the speed limit inbound reduces from 75 to 70 to 55, which is in keeping with the guidance.

I like that reductions are limited, since a drop from 75 to 30 would be difficult, but I'd have no problem with an increase from 30 to 75 if the conditions made that appropriate.  However, another guideline in the manual is that the limit on an undivided road should be the same in both directions, for simplicity of enforcement.  The examples of 55 to 75 outbound and 75 to 70 to 55 inbound are obvious exceptions, but they are for short distances.  The examples I've seen just look like they're saving a single "Speed Limit 70" sign on the outbound side where it isn't really needed.  I've also noticed that the final sign, for "Speed Limit 75," tends to be about halfway between the "70" and "55" signs on the incoming side.  They use one sign placed about halfway between where the "70" and "75" signs technically should be.
Title: Re: Different Direction, Different Speed Limit
Post by: sprjus4 on January 14, 2019, 05:22:12 PM
Quote from: wxfree on January 14, 2019, 01:08:58 AM
Quote from: sprjus4 on January 12, 2019, 08:43:43 PM
I've seen in Texas frequently (on two or four lane) where it will gradually slow down for the town, but outbound it goes from the town speed limit to 55 MPH to 75 MPH. I wonder if it's ever jumped straight to 75 from 35 - 40.

Stops in Texas are basic. Speed limit 75 - four-way stop ahead - Stop - go - speed limit 75. Simple. I love it. One of my favorite states to drive in.

The speed zone manual specifies that speed limits should not change by more than 15 mph, and that a change should not occur less that 0.2 mile from the previous change.  This rule is not always followed.  I know of a place where the limit drops from 50 to 30, and several where it increases from 55 to 75.  At the latter locations, the speed limit inbound reduces from 75 to 70 to 55, which is in keeping with the guidance.

I like that reductions are limited, since a drop from 75 to 30 would be difficult, but I'd have no problem with an increase from 30 to 75 if the conditions made that appropriate.  However, another guideline in the manual is that the limit on an undivided road should be the same in both directions, for simplicity of enforcement.  The examples of 55 to 75 outbound and 75 to 70 to 55 inbound are obvious exceptions, but they are for short distances.  The examples I've seen just look like they're saving a single "Speed Limit 70" sign on the outbound side where it isn't really needed.  I've also noticed that the final sign, for "Speed Limit 75," tends to be about halfway between the "70" and "55" signs on the incoming side.  They use one sign placed about halfway between where the "70" and "75" signs technically should be.
One example I know of that defies this is the U.S. 17 Bypass of Windsor, North Carolina. It drops from 70 MPH to 45 MPH, and vise versa. And it's only 10 years old, you would think it would've been done 70 to 55 then to 45.
Title: Re: Different Direction, Different Speed Limit
Post by: michravera on January 15, 2019, 10:25:55 AM
Quote from: sprjus4 on January 14, 2019, 05:22:12 PM
Quote from: wxfree on January 14, 2019, 01:08:58 AM
Quote from: sprjus4 on January 12, 2019, 08:43:43 PM
I've seen in Texas frequently (on two or four lane) where it will gradually slow down for the town, but outbound it goes from the town speed limit to 55 MPH to 75 MPH. I wonder if it's ever jumped straight to 75 from 35 - 40.

Stops in Texas are basic. Speed limit 75 - four-way stop ahead - Stop - go - speed limit 75. Simple. I love it. One of my favorite states to drive in.

Ontario, OR, one of the few cities in a West Coast state on Mountain Time, was once famous for having a 25 MPH zone through town directly after a long section at the State Maximum with no reduction buffer as is now the "best practice". Welcome to Oregon. Hand over your wallet! I am told that "70 in a 25" was a very common ticket.



The speed zone manual specifies that speed limits should not change by more than 15 mph, and that a change should not occur less that 0.2 mile from the previous change.  This rule is not always followed.  I know of a place where the limit drops from 50 to 30, and several where it increases from 55 to 75.  At the latter locations, the speed limit inbound reduces from 75 to 70 to 55, which is in keeping with the guidance.

I like that reductions are limited, since a drop from 75 to 30 would be difficult, but I'd have no problem with an increase from 30 to 75 if the conditions made that appropriate.  However, another guideline in the manual is that the limit on an undivided road should be the same in both directions, for simplicity of enforcement.  The examples of 55 to 75 outbound and 75 to 70 to 55 inbound are obvious exceptions, but they are for short distances.  The examples I've seen just look like they're saving a single "Speed Limit 70" sign on the outbound side where it isn't really needed.  I've also noticed that the final sign, for "Speed Limit 75," tends to be about halfway between the "70" and "55" signs on the incoming side.  They use one sign placed about halfway between where the "70" and "75" signs technically should be.
One example I know of that defies this is the U.S. 17 Bypass of Windsor, North Carolina. It drops from 70 MPH to 45 MPH, and vise versa. And it's only 10 years old, you would think it would've been done 70 to 55 then to 45.
Title: Re: Different Direction, Different Speed Limit
Post by: Joe The Dragon on January 15, 2019, 11:19:53 AM
Quote from: wxfree on January 14, 2019, 01:08:58 AM
Quote from: sprjus4 on January 12, 2019, 08:43:43 PM
I've seen in Texas frequently (on two or four lane) where it will gradually slow down for the town, but outbound it goes from the town speed limit to 55 MPH to 75 MPH. I wonder if it's ever jumped straight to 75 from 35 - 40.

Stops in Texas are basic. Speed limit 75 - four-way stop ahead - Stop - go - speed limit 75. Simple. I love it. One of my favorite states to drive in.

The speed zone manual specifies that speed limits should not change by more than 15 mph, and that a change should not occur less that 0.2 mile from the previous change.  This rule is not always followed.  I know of a place where the limit drops from 50 to 30, and several where it increases from 55 to 75.  At the latter locations, the speed limit inbound reduces from 75 to 70 to 55, which is in keeping with the guidance.

I like that reductions are limited, since a drop from 75 to 30 would be difficult, but I'd have no problem with an increase from 30 to 75 if the conditions made that appropriate.  However, another guideline in the manual is that the limit on an undivided road should be the same in both directions, for simplicity of enforcement.  The examples of 55 to 75 outbound and 75 to 70 to 55 inbound are obvious exceptions, but they are for short distances.  The examples I've seen just look like they're saving a single "Speed Limit 70" sign on the outbound side where it isn't really needed.  I've also noticed that the final sign, for "Speed Limit 75," tends to be about halfway between the "70" and "55" signs on the incoming side.  They use one sign placed about halfway between where the "70" and "75" signs technically should be.
But there are places where a school zone can drop an 45 down to 25-20.
Title: Re: Different Direction, Different Speed Limit
Post by: wxfree on January 15, 2019, 12:03:32 PM
The speed zone manual I referred to is TxDOT's, so it wouldn't apply to other states.  I assumed that was obvious in context because I don't know of any federal speed limit rules.
Title: Re: Different Direction, Different Speed Limit
Post by: webny99 on November 13, 2019, 03:20:37 PM
I think I may have mentioned this before, but there are three adjacent roadways here (https://www.google.com/maps/@43.1422624,-79.0222047,3a,75y,357.62h,68.99t/data=!3m7!1e1!3m5!1sA-gel-PW0wCw1XjLKaPTUQ!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3DA-gel-PW0wCw1XjLKaPTUQ%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D103.37523%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656), and ALL THREE have different speed limits. And they're not even in the hierarchy that you'd assume: the middle roadway (I-190 NB) has the lowest limit, a ridiculous 45 mph, while being flanked by I-190 SB (65 mph) and NY 265 (55 mph both directions). Pretty crazy that NY 265, the "surface street", gets the higher limit than I-190 NB, the "freeway".
Title: Re: Different Direction, Different Speed Limit
Post by: sprjus4 on November 13, 2019, 09:42:35 PM
Being close to home and traveling it often, I've never thought about this one of having different speed limits until now.

I-264 through the Downtown Norfolk interchange complex, the eastbound lanes are posted at 55 mph, whereas the westbound lanes are only 35 mph, due to sharper curves and twists plus entrance ramps to the left and right in that direction, and a straightaway on the eastbound direction.
Title: Re: Different Direction, Different Speed Limit
Post by: bulldog1979 on November 13, 2019, 11:21:37 PM
Guam Highway 1 (https://en.wikipedia.org/wiki/Guam_Highway_1) has different speed limits in opposite directions.
Title: Re: Different Direction, Different Speed Limit
Post by: TheArkansasRoadgeek on November 14, 2019, 02:26:05 AM
Going east on I-630 (into Little Rock) without construction there's a speed limit of 60, but going west, there's a speed of 55. What I don't get is why you want slower traffic going out of a city center...
Title: Re: Different Direction, Different Speed Limit
Post by: crispy93 on November 15, 2019, 01:03:01 PM
In late 2017, NYSDOT lowered the speed limit on I-84 at the stormville rest area, but only for westbound (downhill) traffic, to 55. The eastbound lanes (going uphill) is still 65.
Title: Re: Different Direction, Different Speed Limit
Post by: vdeane on November 15, 2019, 01:47:56 PM
Quote from: crispy93 on November 15, 2019, 01:03:01 PM
In late 2017, NYSDOT lowered the speed limit on I-84 at the stormville rest area, but only for westbound (downhill) traffic, to 55. The eastbound lanes (going uphill) is still 65.
Looks like that's probably related to an issue with the bridge over NY 52; the street view shows what looks like an indefinite lane shift and shoulder closure.  I see there's a project out there right now, so it's probably temporary.
Title: Re: Different Direction, Different Speed Limit
Post by: renegade on November 16, 2019, 02:04:23 AM
I encountered something along these lines once, years ago.  I can't recall where to save my soul, other than it was somewhere in Ohio.  I only remember it because the ticket was $145.

:colorful:
Title: Re: Different Direction, Different Speed Limit
Post by: crispy93 on November 19, 2019, 03:20:35 PM
Quote from: vdeane on November 15, 2019, 01:47:56 PM
Quote from: crispy93 on November 15, 2019, 01:03:01 PM
In late 2017, NYSDOT lowered the speed limit on I-84 at the stormville rest area, but only for westbound (downhill) traffic, to 55. The eastbound lanes (going uphill) is still 65.
Looks like that's probably related to an issue with the bridge over NY 52; the street view shows what looks like an indefinite lane shift and shoulder closure.  I see there's a project out there right now, so it's probably temporary.

Yes, the bridge project is wrapping up. But for about a year, it was a plain old speed reduction: yellow "55 ahead" signs and several sets of "speed limit 55" signs (I figured they were out of "state speed limit 55" signs and made do). Didn't take long before half of them were falling down or knocked off into the grass. No work zone was set up yet. Within the last few months, they now say "work zone speed limit 55." We'll see what happens.
Title: Re: Different Direction, Different Speed Limit
Post by: vdeane on November 19, 2019, 08:07:10 PM
Quote from: crispy93 on November 19, 2019, 03:20:35 PM
Quote from: vdeane on November 15, 2019, 01:47:56 PM
Quote from: crispy93 on November 15, 2019, 01:03:01 PM
In late 2017, NYSDOT lowered the speed limit on I-84 at the stormville rest area, but only for westbound (downhill) traffic, to 55. The eastbound lanes (going uphill) is still 65.
Looks like that's probably related to an issue with the bridge over NY 52; the street view shows what looks like an indefinite lane shift and shoulder closure.  I see there's a project out there right now, so it's probably temporary.

Yes, the bridge project is wrapping up. But for about a year, it was a plain old speed reduction: yellow "55 ahead" signs and several sets of "speed limit 55" signs (I figured they were out of "state speed limit 55" signs and made do). Didn't take long before half of them were falling down or knocked off into the grass. No work zone was set up yet. Within the last few months, they now say "work zone speed limit 55." We'll see what happens.
Still likely temporary, even then.  I'm guessing some part of the structure was found to be unsafe, resulting in the lane shift, and R8 probably didn't want to have a jersey barrier right up against a travel lane with a 65 mph speed limit.  Last year's street view clearly shows the shift with no work zone.

Such situations aren't unprecedented.  Just look at the 55* mph speed limit on the Thruway through Seneca lands due to poor pavement.

*I think.  Many articles say 45, but they could easily be confusing it with the advisory speed, and the street view isn't current.
Title: Re: Different Direction, Different Speed Limit
Post by: cl94 on November 19, 2019, 10:42:45 PM
Quote from: vdeane on November 19, 2019, 08:07:10 PM
Such situations aren't unprecedented.  Just look at the 55* mph speed limit on the Thruway through Seneca lands due to poor pavement.

*I think.  Many articles say 45, but they could easily be confusing it with the advisory speed, and the street view isn't current.

It was 55 when I was through last year and it remains 55 according to the plans NYSTA posted today for the full-depth rehab.
Title: Re: Different Direction, Different Speed Limit
Post by: amroad17 on November 20, 2019, 02:57:30 AM
I-75 in Northern Kentucky...

SB: 65 mph beginning at Exit 186 (Buttermilk Pike)
NB: 55 mph beginning at Exit 184 (Erlanger)

So, for approximately 2 miles, SB has a 65 mph limit vs. NB at 55 mph.
Title: Re: Different Direction, Different Speed Limit
Post by: hbelkins on November 20, 2019, 09:56:42 AM
I-79 between the West Virginia line and I-70 in Pennsylvania used to have this setup. Different speed limits NB and SB in one area where mine subsidence had been an issue.
Title: Re: Different Direction, Different Speed Limit
Post by: cwf1701 on November 22, 2019, 10:26:15 PM
I-94 near Exit 210 is 70 MPH westbound, 55 Eastbound. The Speed Limit drop Eastbound near Exit 208.
Title: Re: Different Direction, Different Speed Limit
Post by: stevashe on November 23, 2019, 02:16:26 PM
Quote from: cwf1701 on November 22, 2019, 10:26:15 PM
I-94 near Exit 210 is 70 MPH westbound, 55 Eastbound. The Speed Limit drop Eastbound near Exit 208.

Would have been useful if you said what state this was in :-P

Looks like it's in Dearborn, Michigan https://www.google.com/maps/dir/42.2965745,-83.1861785/42.3222003,-83.1640644/@42.315801,-83.1658605,6263m/data=!3m1!1e3!4m2!4m1!3e0
Title: Re: Different Direction, Different Speed Limit
Post by: cwf1701 on November 23, 2019, 09:18:53 PM
Quote from: stevashe on November 23, 2019, 02:16:26 PM
Quote from: cwf1701 on November 22, 2019, 10:26:15 PM
I-94 near Exit 210 is 70 MPH westbound, 55 Eastbound. The Speed Limit drop Eastbound near Exit 208.

Would have been useful if you said what state this was in :-P

Looks like it's in Dearborn, Michigan https://www.google.com/maps/dir/42.2965745,-83.1861785/42.3222003,-83.1640644/@42.315801,-83.1658605,6263m/data=!3m1!1e3!4m2!4m1!3e0
My Bad. there is a reverse between 8 and 10 Mile on I-94 in Detroit, going into Detroit/Wayne County, I-94 drop from 70 to 55 Westbound, and goes to 70 just after the curve south of 9 Mile.
Title: Re: Different Direction, Different Speed Limit
Post by: deathtopumpkins on November 25, 2019, 11:57:52 AM
The Circumferential Highway in NH is posted at 45 eastbound, 50 westbound.
Title: Re: Different Direction, Different Speed Limit
Post by: DevalDragon on April 04, 2020, 03:25:48 AM
On the Indiana Toll Road between the Westgate Toll Plaza and Exit 3 across Wolf Lake is posted at 70 MPH eastbound and 55 MPH westbound.
Title: Re: Different Direction, Different Speed Limit
Post by: bwana39 on April 07, 2020, 11:38:04 AM
Texas doesn't do it even when it makes sense. 

When does it make sense? When a road going one way is through or in acceleration mode. Think a stop sign. It would be prudent to slow traffic before reaching a stop sign or traffic signal. The traffic leaving said impediment with no or significantly distant impediment could / should accelerate at a safe rate up to cruising speed.  Therefore, the speed leaving the intersection should be allowed to accelerate to one posted rate, while the traffic coming toward the impediment should be slowed gradually over distance making the speed limits unmatched across that area.
Title: Re: Different Direction, Different Speed Limit
Post by: vdeane on April 07, 2020, 01:49:20 PM
Quote from: bwana39 on April 07, 2020, 11:38:04 AM
Texas doesn't do it even when it makes sense. 

When does it make sense? When a road going one way is through or in acceleration mode. Think a stop sign. It would be prudent to slow traffic before reaching a stop sign or traffic signal. The traffic leaving said impediment with no or significantly distant impediment could / should accelerate at a safe rate up to cruising speed.  Therefore, the speed leaving the intersection should be allowed to accelerate to one posted rate, while the traffic coming toward the impediment should be slowed gradually over distance making the speed limits unmatched across that area.
I'm not sure I'd agree on that.  Different vehicles take different amounts of time to slow down/stop for something and driving way slow because there's something I'd need to stop for a mile up the road is very frustrating.  This is a mile from customs (https://www.google.com/maps/@43.1364613,-79.0209747,3a,65.8y,340.54h,90.69t/data=!3m6!1e1!3m4!1suOE1CHTwZLqqT0IEbLeZHQ!2e0!7i13312!8i6656) - it's 65 the other way.  This one is a bit over half a mile from a toll barrier to a two-lane bridge (https://www.google.com/maps/@44.2877472,-75.9705494,3a,74.9y,24.19h,87.69t/data=!3m6!1e1!3m4!1sjX32AVcG1G6Ka8B73JA-wA!2e0!7i16384!8i8192) - it's 55 the other way though the cloverleaf in between, 65 on either side of the bridge and interchange.  Here's yet another one (https://www.google.com/maps/@44.0589173,-75.843654,3a,75y,105h,77.03t/data=!3m6!1e1!3m4!1suewMu1DqVoCT6EOcrKhNdg!2e0!7i16384!8i8192), 45 approaching Fort Drum, even though you're half a mile away, and everyone else is getting off at the next interchange anyways.  It's 65 the other way.  Same thing happens approaching I-81 (https://www.google.com/maps/@44.048218,-75.9040575,3a,49.3y,249.04h,88.75t/data=!3m6!1e1!3m4!1sOW7SXoNi2pSlylCWa1Xxxw!2e0!7i16384!8i8192).  In both I-781 examples, people will pass you like you're standing still even if you're speeding by 10 mph.
Title: Re: Different Direction, Different Speed Limit
Post by: webny99 on April 07, 2020, 08:14:39 PM
The I-781 examples are particularly laughable when compared to NY 531... which...
(a) only switches to 55, not 45
(b) remains 65 until much closer to the actual terminus (https://www.google.com/maps/@43.1855225,-77.8503954,3a,34.3y,289.68h,87.11t/data=!3m6!1e1!3m4!1s5UCxT7vOg3xNY0GUENvPkg!2e0!7i13312!8i6656!5m1!1e1), and
(c) ends at an actual stoplight! and not just a freeway ramp.

So if that's not total inconsistency on every possible level, I don't know what is.
Title: Re: Different Direction, Different Speed Limit
Post by: vdeane on April 07, 2020, 08:44:51 PM
Quote from: webny99 on April 07, 2020, 08:14:39 PM
The I-781 examples are particularly laughable when compared to NY 531... which...
(a) only switches to 55, not 45
(b) remains 65 until much closer to the actual terminus (https://www.google.com/maps/@43.1855225,-77.8503954,3a,34.3y,289.68h,87.11t/data=!3m6!1e1!3m4!1s5UCxT7vOg3xNY0GUENvPkg!2e0!7i13312!8i6656!5m1!1e1), and
(c) ends at an actual stoplight! and not just a freeway ramp.

So if that's not total inconsistency on every possible level, I don't know what is.
And not only that, heading straight onto NY 31 west the roadway remains 55, so that drop has more to it than just being to slow people down for the light!
Title: Re: Different Direction, Different Speed Limit
Post by: fwydriver405 on April 08, 2020, 07:04:54 AM
Quote from: Joe The Dragon on January 15, 2019, 11:19:53 AM
Quote from: wxfree on January 14, 2019, 01:08:58 AM
Quote from: sprjus4 on January 12, 2019, 08:43:43 PM
I've seen in Texas frequently (on two or four lane) where it will gradually slow down for the town, but outbound it goes from the town speed limit to 55 MPH to 75 MPH. I wonder if it's ever jumped straight to 75 from 35 - 40.

Stops in Texas are basic. Speed limit 75 - four-way stop ahead - Stop - go - speed limit 75. Simple. I love it. One of my favorite states to drive in.

The speed zone manual specifies that speed limits should not change by more than 15 mph, and that a change should not occur less that 0.2 mile from the previous change.  This rule is not always followed.  I know of a place where the limit drops from 50 to 30, and several where it increases from 55 to 75.  At the latter locations, the speed limit inbound reduces from 75 to 70 to 55, which is in keeping with the guidance.

I like that reductions are limited, since a drop from 75 to 30 would be difficult, but I'd have no problem with an increase from 30 to 75 if the conditions made that appropriate.  However, another guideline in the manual is that the limit on an undivided road should be the same in both directions, for simplicity of enforcement.  The examples of 55 to 75 outbound and 75 to 70 to 55 inbound are obvious exceptions, but they are for short distances.  The examples I've seen just look like they're saving a single "Speed Limit 70" sign on the outbound side where it isn't really needed.  I've also noticed that the final sign, for "Speed Limit 75," tends to be about halfway between the "70" and "55" signs on the incoming side.  They use one sign placed about halfway between where the "70" and "75" signs technically should be.
But there are places where a school zone can drop an 45 down to 25-20.

There's a case in South Berwick ME on SR 236 near Marshwood High School. Speed Limit 55 during normal operations, but near the school, it drops down to 15...
Title: Re: Different Direction, Different Speed Limit
Post by: capt.ron on April 08, 2020, 01:47:58 PM
There is a section of US 59 that straddles TX and AR just north of Texarkana. TX side has a higher speed limit vs AR.