Highest speed limit on a 3di

[kphoger]

Your OP specifically mentioned two 3di highways that are very much not urban.

[Roadgeekteen]

Your OP specifically mentioned two 3di highways that are very much not urban.

Yeah. I think that the toll part of I-470 is also 75.

[GaryV]

In Michigan I-196 doesn't really serve it's purpose as a spur and gets quite aways away from an urban area. It's about 80 miles long. It really should have an even number as both ends are at an interstate.

The original routing of I-196 was a spur - from Grand Rapids to Muskegon.  I-96 was supposed to continue from GR following what is now I-196.

But since all of what is now I-96 was completed first, they didn't think it made sense to have I-96 abruptly change to I-196 on the east side of GR, and the routes were swapped.

[Flint1979]

In Michigan I-196 doesn't really serve it's purpose as a spur and gets quite aways away from an urban area. It's about 80 miles long. It really should have an even number as both ends are at an interstate.

The original routing of I-196 was a spur - from Grand Rapids to Muskegon.  I-96 was supposed to continue from GR following what is now I-196.

But since all of what is now I-96 was completed first, they didn't think it made sense to have I-96 abruptly change to I-196 on the east side of GR, and the routes were swapped.

Yeah I know. It should have got it's number changed at that time. Either I-296 taking the hidden I-296 out and putting that number on 196. Not very many people actually know they are on I-296 when they are anyway.

That would have been a strange routing. Detroit to Lansing to Grand Rapids back down to Benton Harbor. That explains why I-96 ends at US-31 too.

I-196 though currently isn't a spur.

[Roadgeekteen]

In Michigan I-196 doesn't really serve it's purpose as a spur and gets quite aways away from an urban area. It's about 80 miles long. It really should have an even number as both ends are at an interstate.

The original routing of I-196 was a spur - from Grand Rapids to Muskegon.  I-96 was supposed to continue from GR following what is now I-196.

But since all of what is now I-96 was completed first, they didn't think it made sense to have I-96 abruptly change to I-196 on the east side of GR, and the routes were swapped.

Yeah I know. It should have got it's number changed at that time. Either I-296 taking the hidden I-296 out and putting that number on 196. Not very many people actually know they are on I-296 when they are anyway.

That would have been a strange routing. Detroit to Lansing to Grand Rapids back down to Benton Harbor. That explains why I-96 ends at US-31 too.

I-196 though currently isn't a spur.

I guess it's kinda a spur from I-94 to Grand Rapids.

[empirestate]

Is I-680 75 in Nebraska?

I think it's 65.

I-680 and I-29 multiplex. When does I-29 drop in speed limit?

That's in Iowa, not Nebraska.

Additionally, I-680 ends at the southern I-29 junction and no longer overlaps I-29. The piece from the northern I-29 junction to I-80 was renumbered as I-880.

Oh snap how did I not know that.

It used to be that way, it was changed in September 2019.

Likewise snap, I did not know that either. How am I not up on these things anymore? 

[Roadgeekteen]

Is I-680 75 in Nebraska?

I think it's 65.

I-680 and I-29 multiplex. When does I-29 drop in speed limit?

That's in Iowa, not Nebraska.

Additionally, I-680 ends at the southern I-29 junction and no longer overlaps I-29. The piece from the northern I-29 junction to I-80 was renumbered as I-880.

Oh snap how did I not know that.

It used to be that way, it was changed in September 2019.

Likewise snap, I did not know that either. How am I not up on these things anymore? 

I wasn't active on the forum when it changed, it was also only mentioned in the central states board.

[michravera]

Do any of the 80 MPH states have any 3dis to speak of? If I remember my maps correctly, their 3dis tend to be fairly near cities and would therefore be unlikely to be posted higher than 70MPH.

Closest would be the 80 mph and 85 mph segments of SH-130 that serve as a 3di bypass of I-35 near Austin, TX, though it's not actually an interstate highway. I don't believe any actually are posted above 75 mph elsewhere in the country.

TX SH-130 is *NOT* a 3di. But, you are right. Texas is an 80MPH state that has at least quite a few 3dis.

[sprjus4]

Do any of the 80 MPH states have any 3dis to speak of? If I remember my maps correctly, their 3dis tend to be fairly near cities and would therefore be unlikely to be posted higher than 70MPH.

Closest would be the 80 mph and 85 mph segments of SH-130 that serve as a 3di bypass of I-35 near Austin, TX, though it's not actually an interstate highway. I don't believe any actually are posted above 75 mph elsewhere in the country.

TX SH-130 is *NOT* a 3di. But, you are right. Texas is an 80MPH state that has at least quite a few 3dis.

Yes, not a 3di, but the only highway in the state that serves as one that is 80 mph. The only thing preventing actual designation is that it's a toll road. All the actual 3dis top at 70 mph IIRC.

[Flint1979]

In Michigan I-196 doesn't really serve it's purpose as a spur and gets quite aways away from an urban area. It's about 80 miles long. It really should have an even number as both ends are at an interstate.

The original routing of I-196 was a spur - from Grand Rapids to Muskegon.  I-96 was supposed to continue from GR following what is now I-196.

But since all of what is now I-96 was completed first, they didn't think it made sense to have I-96 abruptly change to I-196 on the east side of GR, and the routes were swapped.

Yeah I know. It should have got it's number changed at that time. Either I-296 taking the hidden I-296 out and putting that number on 196. Not very many people actually know they are on I-296 when they are anyway.

That would have been a strange routing. Detroit to Lansing to Grand Rapids back down to Benton Harbor. That explains why I-96 ends at US-31 too.

I-196 though currently isn't a spur.

I guess it's kinda a spur from I-94 to Grand Rapids.

Read what Gary said. If it was a spur to Grand Rapids I believe it would be a child of I-94 instead.

[Roadgeekteen]

In Michigan I-196 doesn't really serve it's purpose as a spur and gets quite aways away from an urban area. It's about 80 miles long. It really should have an even number as both ends are at an interstate.

The original routing of I-196 was a spur - from Grand Rapids to Muskegon.  I-96 was supposed to continue from GR following what is now I-196.

But since all of what is now I-96 was completed first, they didn't think it made sense to have I-96 abruptly change to I-196 on the east side of GR, and the routes were swapped.

Yeah I know. It should have got it's number changed at that time. Either I-296 taking the hidden I-296 out and putting that number on 196. Not very many people actually know they are on I-296 when they are anyway.

That would have been a strange routing. Detroit to Lansing to Grand Rapids back down to Benton Harbor. That explains why I-96 ends at US-31 too.

I-196 though currently isn't a spur.

I guess it's kinda a spur from I-94 to Grand Rapids.

Read what Gary said. If it was a spur to Grand Rapids I believe it would be a child of I-94 instead.

It should be. Maybe I-394.

[cl94]

In Pennsylvania, I-276, I-380, and I-476 all have 70 MPH sections. These are the highest 3DI speed limits you'll find in the Northeast. The common trend with 3 of them is that they're part of of the Pennsylvania Turnpike system.

Maine used to have a 70 MPH limit on I-295, but this was reduced back to 65 due to safety concerns.

For 70, there are MANY examples, including (but not limited to) 580 Nevada, 215 Utah, 435 around Kansas City, and 355 Illinois. It should be noted that Utah will not reduce the speed limit on an Interstate below 70 unless there are severe geometric restrictions.

As far as 75 MPH 3DIs, I think all examples have been covered upthread. The 75-80 MPH states are pretty light on 3DIs in general and states that allow 75-80 almost never allow it in urban/suburban areas, dropping if there is even a house nearby.

[Roadgeekteen]

In Pennsylvania, I-276, I-380, and I-476 all have 70 MPH sections. These are the highest 3DI speed limits you'll find in the Northeast. The common trend with 3 of them is that they're part of of the Pennsylvania Turnpike system.

Maine used to have a 70 MPH limit on I-295, but this was reduced back to 65 due to safety concerns.

For 70, there are MANY examples, including (but not limited to) 580 Nevada, 215 Utah, 435 around Kansas City, and 355 Illinois. It should be noted that Utah will not reduce the speed limit on an Interstate below 70 unless there are severe geometric restrictions.

As far as 75 MPH 3DIs, I think all examples have been covered upthread. The 75-80 MPH states are pretty light on 3DIs in general and states that allow 75-80 almost never allow it in urban/suburban areas, dropping if there is even a house nearby.

Part of I-295 is still 70. Also I-380 isn't part of the Pennsylvania turnpike system (I think).

[sprjus4]

states that allow 75-80 almost never allow it in urban/suburban areas, dropping if there is even a house nearby.

Then there's SH-130 Toll which is 80 mph through a growing suburban area of Austin with intersecting east-west freeways.

[Ketchup99]

In Pennsylvania, I-276, I-380, and I-476 all have 70 MPH sections. These are the highest 3DI speed limits you'll find in the Northeast. The common trend with 3 of them is that they're part of of the Pennsylvania Turnpike system.

Maine used to have a 70 MPH limit on I-295, but this was reduced back to 65 due to safety concerns.

For 70, there are MANY examples, including (but not limited to) 580 Nevada, 215 Utah, 435 around Kansas City, and 355 Illinois. It should be noted that Utah will not reduce the speed limit on an Interstate below 70 unless there are severe geometric restrictions.

As far as 75 MPH 3DIs, I think all examples have been covered upthread. The 75-80 MPH states are pretty light on 3DIs in general and states that allow 75-80 almost never allow it in urban/suburban areas, dropping if there is even a house nearby.

Also I-380 isn't part of the Pennsylvania turnpike system (I think).

Can confirm I-380 is a free road that is not part of the Turnpike system - it was originally part of the I-82 from Scranton to NYC in the early interstate days.

[cl94]

The "3" was a typo. Should have been a "2". I-82 PA was renumbered well before the first section opened.

[bassoon1986]

Express lanes in DFW are indeed 75 mph! Along I-635 and I-820. I think any new build of I-369 anywhere south of Texarkana has a good chance of being signed 75, too.






iPhone

[Roadgeekteen]

The "3" was a typo. Should have been a "2". I-82 PA was renumbered well before the first section opened.

There is no I-280 in PA 

[michravera]

Do any of the 80 MPH states have any 3dis to speak of? If I remember my maps correctly, their 3dis tend to be fairly near cities and would therefore be unlikely to be posted higher than 70MPH.

Closest would be the 80 mph and 85 mph segments of SH-130 that serve as a 3di bypass of I-35 near Austin, TX, though it's not actually an interstate highway. I don't believe any actually are posted above 75 mph elsewhere in the country.

Just because something is a freeway, doesn't make it an interstate. Lots of freeways, especially in Texas and California and Arizona, aren't.

TX SH-130 is *NOT* a 3di. But, you are right. Texas is an 80MPH state that has at least quite a few 3dis.

Yes, not a 3di, but the only highway in the state that serves as one that is 80 mph. The only thing preventing actual designation is that it's a toll road. All the actual 3dis top at 70 mph IIRC.

[roadfro]

I am pretty sure that I-580 in Nevada is posted 70 MPH between Reno and Carson City and north of Reno. I am not sure when the I-580 designation stops and US-395 takes over.

Confirmed that I-580 is 70mph from Eastlake Blvd (just north of Carson City) to SR 431 (first/southernmost interchange in Reno).

There is no 70mph speed on I-580 north of Reno, since I-580 ends at the I-80 interchange in Reno. US 395 north of Reno remains 65mph all the way into California.