Different Direction, Different Speed Limit

[webny99]

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?

[hbelkins]

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?

[signalman]

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.

[vdeane]

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).

[1995hoo]

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.

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

[bzakharin]

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.

[US 89]

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

[cl94]

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.

[signalman]

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 

[roadman65]

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.

[jakeroot]

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.

[pdx-wanderer]

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.

[ftballfan]

60th St on the Kentwood/Gaines Twp boundary near Grand Rapids, MI is 45 eastbound and 55 westbound for a short stretch

[wxfree]

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.

[Bickendan]

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.

[doorknob60]

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)

[pdx-wanderer]

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.

[Bitmapped]

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.

[michravera]

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.

[sprjus4]

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.

[TheHighwayMan3561]

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.

[wxfree]

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.

[sprjus4]

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.

[michravera]

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.

[Joe The Dragon]

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.