Lowest speed limit on an Interstate?

[bugo]

According to Wikipedia, it's 40 MPH.  But I swear I've seen pictures of lower speed limits on Interstates.  What is it?

[1995hoo]

I'm assuming you intend to exclude places like toll plazas or the approaches to Customs checkpoints at the Canadian and Mexican borders and that instead you mean mainline speed limits.

With that understanding, there's a 35-mph speed limit on I-395 in the District of Columbia. I-395 goes down a ramp to enter the Third Street Tunnel and very briefly narrows to a single lane in that area, but it's still part of the mainline and it's posted at 35 mph.

I believe the northbound lanes of I-70 drop to 35 mph some distance before Breezewood, roughly around the point where you cross the access ramp to/from the Turnpike.

[deathtopumpkins]

I-264 in Norfolk, VA has a speed limit of 35, but I'm not sure if there are any static signs displaying that, as that stretch has variable speed limits (I've just never seen anything other than 35 displayed).

I can imagine there are plenty of toll booths with lower speeds (like for instance the barrier tolls on I-90 on the MassPike in Boston), and I'm sure there are some tunnels and interchanges with lower speed limits (I'm thinking of I-90 through the South Bay interchange and the Ted Williams Tunnel then through the airport), though I'm having a hard time verifying these on street view.

Then there's also I-95 at the southern 128 interchange, but I can't remember if the curve speed is regulatory or advisory. Knowing MassDOT I would actually think regulatory.

[TheStranger]

25 MPH (advisory) speed limit for I-75 north transitioning from the Fisher Freeway to the Chrysler Freeway in Detroit:

https://maps.google.com/maps?q=Chrysler+Freeway,+Detroit&hl=en&ll=42.342266,-83.045676&spn=0.004447,0.004265&sll=37.269174,-119.306607&sspn=13.851002,17.468262&t=h&hq=Chrysler+Freeway,&hnear=Detroit,+Wayne,+Michigan&fll=42.342365,-83.0453&fspn=0.004447,0.004265&z=18&layer=c&cbll=42.341914,-83.045669&panoid=WMDMiMES1K6xA4x4WKhuNA&cbp=12,105.55,,1,-8.04

[cpzilliacus]

I-264 in Norfolk, VA has a speed limit of 35, but I'm not sure if there are any static signs displaying that, as that stretch has variable speed limits (I've just never seen anything other than 35 displayed).

I can imagine there are plenty of toll booths with lower speeds (like for instance the barrier tolls on I-90 on the MassPike in Boston), and I'm sure there are some tunnels and interchanges with lower speed limits (I'm thinking of I-90 through the South Bay interchange and the Ted Williams Tunnel then through the airport), though I'm having a hard time verifying these on street view.

One of the smarter things I've seen in Europe is an END MOTORWAY sign as one approaches a mainline toll barrier (GSV example here on Route E20 approaching the bridge-tunnel toll plaza in Malmö, Sweden).

The speed limit goes down to 70 k/h and then to 30 k/h and finally to 10 k/h at the toll booths (this barrier does double duty, as traffic headed from Denmark to Sweden is subject to customs enforcement (if you look carefully on GSV, you can see a VACIS truck north of the toll barrier - I suspect Swedish customs officers are looking for (large quantities of) smuggled alcohol, drugs and maybe human beings), as both nations belong to the Schengen agreement, they are presumably not doing immigration checks or stamping passports).   

Though I don't the the gamma rays used by VACIS are good for living things.

[roadman]

I-264 in Norfolk, VA has a speed limit of 35, but I'm not sure if there are any static signs displaying that, as that stretch has variable speed limits (I've just never seen anything other than 35 displayed).

I can imagine there are plenty of toll booths with lower speeds (like for instance the barrier tolls on I-90 on the MassPike in Boston), and I'm sure there are some tunnels and interchanges with lower speed limits (I'm thinking of I-90 through the South Bay interchange and the Ted Williams Tunnel then through the airport), though I'm having a hard time verifying these on street view.

Then there's also I-95 at the southern 128 interchange, but I can't remember if the curve speed is regulatory or advisory. Knowing MassDOT I would actually think regulatory.

The 25 mph limit on the "Canton Death Curve" from I-95 north to I-95/128 north is advisory, not regulatory.  Same goes for the 25 mph limit on the "Attleboro Death Curve" from I-295 north to I-95 north.

[agentsteel53]

(if you look carefully on GSV, you can see a VACIS truck north of the toll barrier - I suspect Swedish customs officers are looking for (large quantities of) smuggled alcohol, drugs and maybe human beings),

does all traffic get shunted to using the VACIS?  I couldn't really tell because there was a break in Google imagery between the toll plaza and the point where you're almost right next to the truck.

when I crossed the bridge, I did not get any customs check in either direction.  there also were no human toll operators, as far as I could find.  it was 4am one time and 3.30am the other.  I was glad my US credit card was accepted without needing a PIN.

[PHLBOS]

I-295 southbound at the I-76/NJ 42 interchange has a posted speed (regulatory speed limit) of 35 shortly before the infamous Al-Jo curve.

[mgk920]

What is the speed limit on I-94 through the tunnel at Hennepin Ave in Minneapolis, MN?

Mike

[cpzilliacus]

(if you look carefully on GSV, you can see a VACIS truck north of the toll barrier - I suspect Swedish customs officers are looking for (large quantities of) smuggled alcohol, drugs and maybe human beings),

does all traffic get shunted to using the VACIS?  I couldn't really tell because there was a break in Google imagery between the toll plaza and the point where you're almost right next to the truck.

I don't think so (but I don't know with certainty) - for one thing, if they screened every vehicle with VACIS, they would back up traffic back to Kastrup Airport in Denmark!

My impression is they use VACIS when they already have a suspicion that contraband might be hidden in a vehicle.   From what I can tell on Border Wars (airs on the National Geographic Channel), that's how U.S. ICE agents use such units at the U.S./Mexico border and (sometimes) at inland checkpoints.

when I crossed the bridge, I did not get any customs check in either direction.  there also were no human toll operators, as far as I could find.  it was 4am one time and 3.30am the other.  I was glad my US credit card was accepted without needing a PIN.

My understanding was that they accept cash (Swedish, Danish and Euros) at all times.  But maybe not.

I also understand that Danish customs does not check traffic headed from Sweden to Denmark (but they probably reserve the right to).

[maplestar]

I-264 in Norfolk, VA has a speed limit of 35, but I'm not sure if there are any static signs displaying that, as that stretch has variable speed limits (I've just never seen anything other than 35 displayed).

I've seen a static 35 sign just as you're coming out of the tunnel towards Norfolk (eastbound), where the lanes from I-464 are joining before the Berkley Bridge. I have also seen 25 displayed on the variable speed limit signs (at least westbound, before the bridge), and that may be part of the protocol for stopping traffic for a bridge opening, based on the most recent times I've noticed it at 25.

[jeffandnicole]

I-295 southbound at the I-76/NJ 42 interchange has a posted speed (regulatory speed limit) of 35 shortly before the infamous Al-Jo curve.

And Northbound in the same area as well.

[roadman]

What is the speed limit on I-94 through the tunnel at Hennepin Ave in Minneapolis, MN?

Mike

35 mph, but that's advisory, not regulatory (my best friend used to live in the Twin Cities, so I recall both the I-94 tunnel and the original I-35W bridge very well).

The I-93 tunnels through Downtown Boston are regulatory 45 mph, but advisory 35 mph on the curves.

[sipes23]

I forget the posted limit (45 is memory serves), but the curve on I-90 just west of downtown Cleveland is posted pretty low.

[Special K]

25 MPH (advisory) speed limit for I-75 north transitioning from the Fisher Freeway to the Chrysler Freeway in Detroit:

https://maps.google.com/maps?q=Chrysler+Freeway,+Detroit&hl=en&ll=42.342266,-83.045676&spn=0.004447,0.004265&sll=37.269174,-119.306607&sspn=13.851002,17.468262&t=h&hq=Chrysler+Freeway,&hnear=Detroit,+Wayne,+Michigan&fll=42.342365,-83.0453&fspn=0.004447,0.004265&z=18&layer=c&cbll=42.341914,-83.045669&panoid=WMDMiMES1K6xA4x4WKhuNA&cbp=12,105.55,,1,-8.04

Advisories are not limits.

[PHLBOS]

The I-93 tunnels through Downtown Boston are regulatory 45 mph, but advisory 35 mph on the curves.

Its Central Artery predecessor had a posted regulatory 35 mph limit.

[kphoger]

According to Wikipedia, it's 40 MPH.  But I swear I've seen pictures of lower speed limits on Interstates.  What is it?

An enigma.

[mcdonaat]

Interstate 10 eastbound between La 30 (Nicholson/TO LSU) and Washington Street (basically the ramp from the I-10 bridge to 110) has a posted speed limit of 35, and the fastest you can go is 40 MPH.

[InterstateNG]

This one?:  https://maps.google.com/maps?q=Baton+Rouge,+LA&hl=en&ll=30.439054,-91.182511&spn=0.009269,0.01929&sll=30.307761,-97.753401&sspn=0.59398,1.234589&oq=Baton&hnear=Baton+Rouge,+East+Baton+Rouge,+Louisiana&t=m&z=16&layer=c&cbll=30.439055,-91.18231&panoid=8mgg-iqkDdx8SgeIgrDQlw&cbp=12,113.29,,0,8.73

[NE2]

Technically this 30 mph is still on I-175:

And this one on I-375 (yeah, it's past the end sign, but those often jump the gun slightly):

As well as the east end of I-195 FL (this one is definitely before the former end sign, now gone).

25 mph at the east end of I-70:


The only others below 35 currently tagged in OSM are at toll booths.

[rarnold]

45 MPH - Downtown Loop, Kansas City, MO

[NE2]

45 MPH - Downtown Loop, Kansas City, MO

[pooing is uncool] → [45<40]

[rickmastfan67]

According to Wikipedia, it's 40 MPH.  But I swear I've seen pictures of lower speed limits on Interstates.  What is it?

Well, here's one of those 40mph's, I-279 @ it's Southern start.

[kphoger]

[pooing is uncool] ↔ [45<40]

FTFY.  Iff.

[deathtopumpkins]

I-264 in Norfolk, VA has a speed limit of 35, but I'm not sure if there are any static signs displaying that, as that stretch has variable speed limits (I've just never seen anything other than 35 displayed).

I've seen a static 35 sign just as you're coming out of the tunnel towards Norfolk (eastbound), where the lanes from I-464 are joining before the Berkley Bridge. I have also seen 25 displayed on the variable speed limit signs (at least westbound, before the bridge), and that may be part of the protocol for stopping traffic for a bridge opening, based on the most recent times I've noticed it at 25.

I honestly can't remember the last time I got stopped for a bridge opening at the Berkley (only the JRB and Coleman, but they don't have variable speed limit signs), but yes, reducing the speed to 25 is standard protocol for a Hampton Roads tunnel closure and presumably a bridge closure too.



Another case of technically before the end sign: http://goo.gl/maps/PGKsC I-264 in Virginia Beach. Drops to 45 then 35 between the Birdneck interchange and the first intersection.