Longest stretch of six-laned highways

[golden eagle]

I remember I-5 being at least six lanes from San Diego to Los Angeles. I'm willing to be it's even longer on I-95 from at least northern Virginia to Connecticut or even beyond.

[froggie]

Not necessarily.  You have two gaps on I-95 at its interchanges with the DC Beltway, then I-95 is 4 lanes through Wilmington, DE, then you have a gap in I-95 itself in Jersey.  Outside of Florida, the longest single stretches on I-95 would probably be Petersburg (I-85) to the Springfield Interchange (I-395/495), then from the DC Beltway on the north end to I-495 in Wilmington.

[AZDude]

I-10 from Indio to it's western terminus.  (aprox 146 miles).

I-15 from near its beginning in San Deigo to (Future) North Las Vegas. (Not sure how long it would be)

[brad2971]

I-15 is only 4 lanes from I-40 to the Nevada border (climbing lanes notwithstanding), and there's no indication that two extra lanes will be built anytime soon.

However, on the East Coast, I-75 is very close to being six lanes from north of Atlanta to the Florida Turnpike.

[corco]

I-5 in Washington is 6-laned from MP 95 at the southerly SR 121 interchange all the way to MP 223 on the south side of Mount Vernon, 128 miles, with loose plans to widen it all the way to Portland, and fairly definite plans to widen it as far down as Chehalis

[agentsteel53]

if you want to count a route with multiple numbers, then isn't 495 around Wilmington three lanes, and then 295 to the Jersey Turnpike?

[SSOWorld]

I-80 from western terminus all the way to Auburn (NE of Sacramento)  it's at least 6 lanes - could be up to 12.

[AZDude]

I-15 is only 4 lanes from I-40 to the Nevada border (climbing lanes notwithstanding), and there's no indication that two extra lanes will be built anytime soon.

However, on the East Coast, I-75 is very close to being six lanes from north of Atlanta to the Florida Turnpike.

I was under the impression that plans called for I-15 to be at least six lanes from San Deigo to LV.  Maybe they were dropped.

[mapman]

I remember I-5 being at least six lanes from San Diego to Los Angeles.

Actually, it's longer than that -- from the US/Mexico Border to CA 99 near Wheeler Ridge, CA -- about 220 miles total.

[Duke87]

Handling interchanges in this qualification can be tricky.

For instance, 95 northbound where it joins 695 (NY) has to briefly drop down to two lanes before the merge. However, directly opposite it at that point, 95 southbound is four lanes preparing to split. So does that count?
Not that it really matters much anyway, since just south of here 95 southbound actually drops to one (yes, one!) lane to merge onto the Cross Bronx while 95 northbound is again only two lanes for its ramp.

Still, working north from there, you have 6+ lanes to the junction with I-91 in New Haven. That's 63 miles. Not too shabby.

The aforementioned Virginia segment would be between exits 84B and 170. 86 miles. Okay, that's longer. Still not longer than the I-10 segment, but...
..if we're willing to ignore brief drops in lane count at interchanges (which I am), then we have a 6+ lane run straight from Petersburg to Wilmington (specifically Virginia exit 50A to Delaware exit 6), which is 251 miles.
And if we allow for the future plans of swapping 95 and 495, and connecting to and widening the PA turnpike and bridge... then Branford is the north end of all that (exit 54), for a grand total of 455 miles. But then we're counting chickens before they hatch...

[Greybear]

I-30 is a minimum of six lanes from its terminus at I-20 in Parker County to Exit 68 (TX 205) in Rockwall for a distance of 68 miles.

I-45 is a minimum of six lanes from just north of Corsicana (Exit 235) to its terminus at I-30 (Exit 284) in Dallas for a total of 49 miles.

I-20 in Texas is a minimum of six lanes from Exit 414 (US 180 West) to Exit 421 (I-30 East) for a length of 7 miles. It drops to four lanes from I-30 to Exit 428 (I-820 North). From there to Exit 480 (I-635 North) it maintains a minimum of six lanes for a length of 52 miles. Most of the length of I-20 from I-35W (Exit 437) to I-635 is eight lanes.

[mightyace]

Maybe someone else can tell me how far it goes on both ends, but I know I-75 is 6 lanes from I-24 near Chattanooga to Atlanta.

I think it is six lanes for several miles north of that as well as south of Atlanta, but I have no idea how far.

I-40 around Knoxville is at least six lanes from the I-75 South junction (exit 368) to the I-81 junction (exit 421) or 53 miles.

[Chris]

While American urban freeways are obviously wider than European freeways, I think European freeways have more rural 6-lane parts, because the European countryside is generally more densely populated.

Examples;

Germany: A2 Oberhausen - Berlin 6 lanes for 300 miles*
Germany: A9 Berlin - München 6 lanes for 325 miles*
Turkey: O-4 Istanbul - Ankara 6 lanes for 270 miles
France: A7 Lyon - Marseille 6 lanes for 175 miles
Austria: A1 Salzburg - Wien 6 lanes for 165 miles
France: A1 Paris - Lille 6 lanes for 130 miles

Almost all of Britain's motorways are 6 laned.

* each of them still has a small gap, which is U/C

[froggie]

However, on the East Coast, I-75 is very close to being six lanes from north of Atlanta to the Florida Turnpike.

Except through Macon, where it will stay 4 lanes.

if you want to count a route with multiple numbers, then isn't 495 around Wilmington three lanes, and then 295 to the Jersey Turnpike?

Not for either.  Southbound I-495 is briefly 4 lanes through its southern interchange with 95/295, and both directions are 4 lanes near the north end between US 13 and the merge/split with 95 at the DE/PA line.  I-295 is also 4 lanes through the interchange with 95/495.

..if we're willing to ignore brief drops in lane count at interchanges (which I am)

By definition, if the lane isn't carried through the interchange, it's not a through lane.

Maybe someone else can tell me how far it goes on both ends, but I know I-75 is 6 lanes from I-24 near Chattanooga to Atlanta.

I think it is six lanes for several miles north of that as well as south of Atlanta, but I have no idea how far.

North end is correct (though 75 is 6+ lanes north of 24, it's only 4 lanes through the interchange at 24).  South end of that stretch is the 475 split north of Macon.


Another lengthy one to consider:  the Ohio Turnpike.  Not sure if the 6-laning is completed through the Cleveland area yet, but if so, then I-80/Ohio Turnpike is 6 lanes from I-75 (Exit 64) to I-76 (Exit 218) or 154 miles.

[Brandon]

There's the I-94/I-294/I-94 roadway that includes the Tri-State Twy from Exit 34 (I-196) in Benton Harbor, MI to the south side of Milwaukee (I-894/I-43) that is entirely three lanes or more per direction.  It's about 195 miles long.

[haljackey]

Here's the longest stretch of six-laned highway in Canada.  Its along Highway 401 between Highway 402 and Highway 10, and is about 300km long.  In the Toronto area, the highway swells to as many as 18 lanes.

[agentsteel53]

alas, through the East LA Interchange, I-5 drops to an incredible one lane.

[agentsteel53]

the plans also called for I-95 to be more than zero lanes in Somerset County, NJ. 

[leifvanderwall]

I think I-75 from Bay City, Mi. to the Ohio Turnpike could be in the running for one of the longest stretches with 6+ lanes. I-94 from I-196 to US 23 in Michigan could be one of the longest stretches of highway that should be 6 lanes but is only 4 (except for the small, tiny stretch in Kalamazoo, you perfectionists).

[brad2971]

"Except through Macon, where it will stay 4 lanes."

Since I-475 is the outer bypass of Macon, are there any plans to 6-lane that by GDOT? Or would Macon get into a snit about "lost traffic?"

[froggie]

Most of the bypass is already 6 lanes.  The exceptions being at either end...last 1/2 mile or so on the south end, and north of the US 41 interchange on the north end.  Reason being for lane balance at the merges/splits with I-75.  Making 475 continuously 6 lanes would, at a minimum, require building auxiliary lanes on 75 heading outward from each side.

[jdb1234]

In Alabama, the longest 6 lane stretch of highway is I-65 from exit 246 to just south of exit 291.

[rawmustard]

I think I-75 from Bay City, Mi. to the Ohio Turnpike could be in the running for one of the longest stretches with 6+ lanes.

I wouldn't think the transition to the Chrysler from the Fisher in Detroit would be six lanes, though. Those are still one-lane ramps each way IIRC.

[Chris]

The longest six-lane freeway may be in.... Algeria!

They are currently constructing a 1200 kilometer (750 mile) east-west freeway, and the completed parts in Google Earth (with recent imagery) all show 6 lanes. The Chinese are constructing that freeway.

[74/171FAN]

I-95 is basically at least 6 lanes from I-4 in Daytona Beach, FL to the GA-SC line with the exception of the I-10 interchange in Jacksonville mainly due to that construction.  One day it'll probably extend to the 6-lane section starting at I-85 due to increasing traffic but due to funding concerns that'll be years away