Interstate one lane mainlines

[Alex]

I-90 in western Montana's 2 lanes each way.  At one point they were separated by a double yellow line, but word is that the state put in a Jersey barrier sometime within the past decade or so.

Indeed it is now a jersey barrier median.

[roadman65]

Does not I-83 in Harrisburg, PA at the I-283 have it narrow down to single lane?

[PAHighways]

Yes as well as on the western shore where it intersects PA 581.

[ftballfan]

WB I-96 drops to one lane briefly at Exit 30 north of Grand Rapids.

http://maps.google.com/maps?hl=en&ie=UTF8&ll=43.016948,-85.681643&spn=0,0.028067&z=16&layer=c&cbll=43.016861,-85.682801&panoid=9e0lswYQwgb8bskomi_03g&cbp=12,263.78,,0,8.46

The left lane is mainline I-96 while the right lane is an exit only lane to SB Alpine Ave. Coming in from the left is two lanes from US-131, one of which ends between this interchange and the next interchange, resulting in two travel lanes westbound.

[hbelkins]

I-70 eastbound in Kansas City, Kan. narrows to one lane.

[Ace10]

To continue on I-80 going eastbound just east of the Indiana-Illinois state line, you have to exit from I-94 onto a one-lane ramp, and then onto I-90. The ramp does briefly become two-lane with the westbound I-94 ramp. Same goes for the interchange in the opposite direction.

41.589142N, 87.233052 W

[SteveG1988]

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Trenton+NJ&aq=&sll=40.184144,-74.716581&sspn=0.00382,0.010504&gl=us&ie=UTF8&hq=&hnear=Trenton,+Mercer,+New+Jersey&ll=40.183923,-74.716387&spn=0.030295,0.084028&t=h&z=14&layer=c&cbll=40.184144,-74.716581&panoid=gf22INXv1iyRdmMYu6inUQ&cbp=12,277.49,,0,0.28

Interstate 195 in NJ, the future path will take it up the ramp on the right to continue north to where 295 and 95 meet at US1

[vtk]

Seems there are multiple threads for this...

I-71 is routed through a single-lane ramp each way through the Mound-Sandusky (West Split) Interchange (Jct I-70 & OH-315) in Columbus.  I-70 Westbound is forced into a single lane just before joining I-71 Southbound in the East Split Interchange; there's another lane there but it's Exit Only for 4th Street.  Both of these situations are supposed to be rectified as the I-70/71 project takes its course, giving I-70 and I-71 three and two through lanes each way, respectively.  (Or so says the overall description -- for some reason, the actual plans show only two through lanes westbound on I-70 through both major interchanges...)

Also, I think NB I-71 narrows to a single lane just before merging with I-75 in northern Kentucky.  Now why couldn't they have let the two Interstates join, and then drop a lane a bit downstream?

[Stephane Dumas]

Not an interstate, some Quebec autoroutes do the same thing.

At Longueuil, A-20 eastbound when it left the PQ-132 multiplex at the junction of TCH-25
http://maps.google.com/?ll=45.577125,-73.477818&spn=0.002628,0.013733&z=17&layer=c&cbll=45.577124,-73.477815&panoid=o1wIjszAaRxm3LKCSXvGQg&cbp=11,59.48,,0,1.69
and at the junction of A-10
both A-20 and A-15 left the multiplex with PQ-132 to reach A-10 and Champlain bridge with one lane ramp
http://maps.google.com/?ll=45.475533,-73.500059&spn=0.002633,0.013733&z=17&layer=c&cbll=45.475531,-73.500063&panoid=z8GVF9-p0LqOIl6XK9BHKg&cbp=11,152.72,,0,2.25

A-55 northbound at Magog, when it begin a multiplex with A-10
http://maps.google.com/?ll=45.291222,-72.123871&spn=0.010567,0.054932&z=15&layer=c&cbll=45.291227,-72.123876&panoid=gfghwn76Ps_9pRQ1a9sWqw&cbp=11,307.42,,0,4.15

A-55 do it again later, on both directions between Drummondville and Ste-Eulalie when it got multiplexed with TCH-20
http://maps.google.com/?ll=46.091418,-72.248712&spn=0.010417,0.054932&z=15&layer=c&cbll=46.091426,-72.248706&panoid=SLiVlRpQYXd66CGNIk_lxQ&cbp=11,50.81,,0,3.23 

[Revive 755]

* EB I-94 where it leaves the Tri-State and merges with US 41:

http://maps.google.com/maps?hl=en&ll=42.135913,-87.788744&spn=0.053655,0.132093&z=14&layer=c&cbll=42.145379,-87.796593&panoid=Ue9GubIoLHbDp0UW_dHzHQ&cbp=12,116.11,,0,2.22

Traffic wise, this design is horrible.

[texaskdog]

Maybe I'm remembering wrong but how about Glenwood Canyon in Colorado?

[Brandon]

Maybe I'm remembering wrong but how about Glenwood Canyon in Colorado?

You're remembering wrong.  I went through there in October, and the whole thing was two lanes in each direction.

[Brandon]

* EB I-94 where it leaves the Tri-State and merges with US 41:

http://maps.google.com/maps?hl=en&ll=42.135913,-87.788744&spn=0.053655,0.132093&z=14&layer=c&cbll=42.145379,-87.796593&panoid=Ue9GubIoLHbDp0UW_dHzHQ&cbp=12,116.11,,0,2.22

Traffic wise, this design is horrible.

Yes, it is bad, but you have two lanes from the Spur merging with two lanes from the Edens here, and the Edens has three lanes.  The Edens could use another lane until the next exit and eliminate this problem.  Thank IDiOT for that fuckup.

[texaskdog]

yeah i believe it was just the road decks one over the other, i believe youre right it was 2 lanes each way, just tight

[mtantillo]

Not an interstate, some Quebec autoroutes do the same thing.

and at the junction of A-10
both A-20 and A-15 left the multiplex with PQ-132 to reach A-10 and Champlain bridge with one lane ramp
http://maps.google.com/?ll=45.475533,-73.500059&spn=0.002633,0.013733&z=17&layer=c&cbll=45.475531,-73.500063&panoid=z8GVF9-p0LqOIl6XK9BHKg&cbp=11,152.72,,0,2.25

This one should get a special honorable mention, because not only does it narrow to one lane ramps twice (bridge ramps and slip ramps from the QC 132 freeway), but it utilizes a frontage road that isn't even a freeway!  Though I suppose that is allowed in Quebec (for example, A-20).

[MeanMeosh]

Does I-93 in New Hampshire still narrow to one lane in each direction through Franconia Notch?

[agentsteel53]

Does I-93 in New Hampshire still narrow to one lane in each direction through Franconia Notch?

it did the last time I was there, which was April, 2008.

I do not remember if that segment is considered I-93, or a gap in the route.  I can never remember.

[Dr Frankenstein]

It is I-93 AFAIK. And it's still one lane per direction AFAIK.

[qguy]

Does not I-83 in Harrisburg, PA at the I-283 have it narrow down to single lane?

Yes as well as on the western shore where it intersects PA 581.

I-83 is one lane in both directions through both the I-283 and the PA 581 interchanges--approximately 4-1/2 miles apart. In addition, at each interchange I-83 in one of its directions uses an offramp to continue.

Southbound on I-83 at PA 581, one has to exit the mainline to the right to continue on I-83 (through a single-lane trumpet interchange). The mainline continues west with two lanes as PA 581.

Northbound on I-83 at the interchange with I-283 and US 322 (the infamous Eisenhower Interchange), one has to exit the mainline to the left to continue on I-83 (using a single-lane flyover ramp). The mainline continues east with two lanes as US 322.

Not as remarkable, since it's a termination point, but worthy of mentioning I suppose: I-283 begins/ends at the Eisenhower Interchange; it is one lane in both directions to and from every connection with both I-83 and US 322 (six one-lane ramps).

[WillWeaverRVA]

It is I-93 AFAIK. And it's still one lane per direction AFAIK.

Yes and yes, according to Google Street View, anyway.

[mtantillo]

It is I-93 AFAIK. And it's still one lane per direction AFAIK.

Yes.  Used to be signed as "US 3, Franconia Notch Parkway, to I-93", but is now signed "I-93/US 3, Franconia Notch Parkway". 

[mgk920]

Westbound I-70 drops to one lane at the tunnel in Wheeling, WV.

Until it is rebuilt (soon, I have seen the plans), I-55 at the east end of its Mississippi River bridge in Memphis goes through one-lane ramps while making that turn at the cloverleaf interchange.

I-43 follows one-lane ramps in both directions through the Hale Interchange (US 45/I-894 splits) in Greenfield (suburban Milwaukee), WI.

Mike

[1995hoo]

Inbound (northbound) I-395 VERY briefly narrows to one lane as it goes around the ramp from the Southwest-Southeast Freeway onto what used to be known as the Center Leg Freeway (more commonly called the 3d Street Tunnel these days). The single-lane distance is rather minuscule, but it's there.

[ChezeHed81]

I-76 EB in Philadelphia, PA, is 3 lanes approaching interchange #347.  The left (Penrose Av to I-95 SB [347 A]) and center (Passyunk Av [347 B]) lanes are unlabeled "exit only", and all thru traffic must merge into the right lane.  Before one is completely thru this interchange, each route has already expanded to 2 lanes, but I-76 is briefly signed and striped as a 1-lane mainline.

[texaskdog]

All the Interstates in Alaska