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National Boards => General Highway Talk => Topic started by: fillup420 on December 08, 2019, 09:36:58 PM

Title: interesting and unique road design
Post by: fillup420 on December 08, 2019, 09:36:58 PM
I recently drove up I-85 from Charlotte to Raleigh NC. there is a point where the northbound and southbound lanes switch sides and weave around a bit before returning the the correct side. Its out in the middle of the woods with only 1 exit to a rest area; I could not see a reason for it to be built in such a way.
Title: Re: interesting and unique road design
Post by: 1995hoo on December 08, 2019, 10:03:17 PM
Quote from: fillup420 on December 08, 2019, 09:36:58 PM
I recently drove up I-85 from Charlotte to Raleigh NC. there is a point where the northbound and southbound lanes switch sides and weave around a bit before returning the the correct side. Its out in the middle of the woods with only 1 exit to a rest area; I could not see a reason for it to be built in such a way.

It's to give right-lane access to the rest area, and the state's Vietnam Veterans memorial, located in the middle of the highway in that area.
Title: Re: interesting and unique road design
Post by: sprjus4 on December 08, 2019, 10:07:00 PM
I-5 north of Los Angeles, CA does a similar switch over. No rest areas or anything significant shared in the median, so who knows.

https://www.google.com/maps/@34.5253246,-118.6464463,11039m/data=!3m1!1e3
Title: Re: interesting and unique road design
Post by: sprjus4 on December 08, 2019, 10:08:56 PM
Quote from: 1995hoo on December 08, 2019, 10:03:17 PM
Quote from: fillup420 on December 08, 2019, 09:36:58 PM
I recently drove up I-85 from Charlotte to Raleigh NC. there is a point where the northbound and southbound lanes switch sides and weave around a bit before returning the the correct side. Its out in the middle of the woods with only 1 exit to a rest area; I could not see a reason for it to be built in such a way.

It's to give right-lane access to the rest area, and the state's Vietnam Veterans memorial, located in the middle of the highway in that area.
Interestingly enough, they recently closed 4 rest areas on I-77, and replaced it with one single median rest area, but since the lanes do not swap like I-85, you exit / enter left to access it. Poor design, IMO, especially with large trucks, which there's a decent amount on I-77.

https://www.google.com/maps/@35.9001874,-80.8563603,1357m/data=!3m1!1e3
Title: Re: interesting and unique road design
Post by: ilpt4u on December 09, 2019, 12:37:26 AM
Quote from: sprjus4 on December 08, 2019, 10:07:00 PM
I-5 north of Los Angeles, CA does a similar switch over. No rest areas or anything significant shared in the median, so who knows.

https://www.google.com/maps/@34.5253246,-118.6464463,11039m/data=!3m1!1e3
Appears there is a RIRO Frontage Road on the Wrong Way Segment that grants some Local Access to the median

Without the Crossover, that Median Access Road would have to be LILO...not as nice on a Freeway
Title: Re: interesting and unique road design
Post by: CtrlAltDel on December 09, 2019, 01:10:09 AM
Quote from: fillup420 on December 08, 2019, 09:36:58 PM
I recently drove up I-85 from Charlotte to Raleigh NC. there is a point where the northbound and southbound lanes switch sides and weave around a bit before returning the the correct side. Its out in the middle of the woods with only 1 exit to a rest area; I could not see a reason for it to be built in such a way.

For others who are curious, I believe that the rest area in question is here:
https://www.google.com/maps/place/35.8402818,-80.1338996
Title: Re: interesting and unique road design
Post by: sprjus4 on December 09, 2019, 01:11:12 AM
^ That's the one, south of High Point on I-85.
Title: Re: interesting and unique road design
Post by: bemybear on January 07, 2020, 03:01:21 PM
Quote from: sprjus4 on December 08, 2019, 10:07:00 PM
I-5 north of Los Angeles, CA does a similar switch over. No rest areas or anything significant shared in the median, so who knows.

https://www.google.com/maps/@34.5253246,-118.6464463,11039m/data=!3m1!1e3

The famous Grapevine crossover is done to provide a less steep uphill climb by having the lanes swap in that section.
https://www.quora.com/Why-does-the-eight-lane-I5-freeway-switch-sides-for-several-miles-on-the-Grapevine-north-of-Los-Angeles-Why-is-oncoming-traffic-on-this-stretch-on-the-right-and-the-not-left-Seems-needlessly-expensive

https://boards.straightdope.com/sdmb/archive/index.php/t-795294.html

Obviously the roads end up at the same elevation but the downhill side is on a more severe slope than the uphill side with the cross over.