AARoads Forum

National Boards => General Highway Talk => Topic started by: tolbs17 on January 03, 2020, 04:57:30 PM

Title: What is the best interchange and why are they chosen?
Post by: tolbs17 on January 03, 2020, 04:57:30 PM
http://prntscr.com/qj2h5z

When I saw these two interchanges it made me ask this question.

_________________________________________________________


Diamond - useful anywhere really, most common in rural areas.

Parclo A2/B2 interchange - useful in more developed areas.

Advantages - uses up less space

Disadvantages - slows traffic down and you can't accelerate as fast when you are trying to go on the freeway (depends in what direction the interchange is in).

Parclo A4 - useful at busy interchanges.

Parclo B4 - useful at busy interchanges, can be an advantage if you don't want to build a fucking DDI, haha

Diverging Diamond Intercahnge (DDI) - useful in moderately developed areas.

Folded diamond - useful anywhere really but I said the same thing for Parclo B2.

That screenshot was taken from the proposal of Complete 540 (which is now under construction) and the orange one was selected because it has the least impacts.
Title: Re: What is the best interchange and why are they chosen?
Post by: kphoger on January 03, 2020, 05:07:03 PM
Don't get tradephoric started on the ParClo B4 vs DDI . . .
Title: Re: What is the best interchange and why are they chosen?
Post by: Big John on January 03, 2020, 06:48:35 PM
SPUI - Used in urban areas with turning movemenys
Title: Re: What is the best interchange and why are they chosen?
Post by: tolbs17 on January 03, 2020, 06:53:16 PM
Quote from: Big John on January 03, 2020, 06:48:35 PM
SPUI - Used in urban areas with turning movemenys
Advantages - very useful for large vehicles such as trucks and buses.

Disadvantages - requires wider bridges
Title: Re: What is the best interchange and why are they chosen?
Post by: US 89 on January 03, 2020, 08:03:39 PM
Folded diamonds are most useful in cases where a railroad line runs parallel to the intersecting roadway, as freeway ramps can't cross train tracks at grade.
Title: Re: What is the best interchange and why are they chosen?
Post by: tolbs17 on January 03, 2020, 09:27:02 PM
Quote from: US 89 on January 03, 2020, 08:03:39 PM
Folded diamonds are most useful in cases where a railroad line runs parallel to the intersecting roadway, as freeway ramps can't cross train tracks at grade.
Yeah, but sometimes they build bridges if they really want it to be a diamond or they have nothing to do about it.

Examples:

Old Stantonsburg Rd (https://www.google.com/maps/@35.6678595,-77.8847989,15.09z)

US Highway 301 (https://www.google.com/maps/@35.6689046,-77.961245,14.84z)
Title: Re: What is the best interchange and why are they chosen?
Post by: thspfc on January 03, 2020, 09:43:02 PM
I know cloverleaves suck, but they are aesthetically pleasing, like this one: https://www.google.com/maps/@41.3686562,-89.0616738,15.74z (https://www.google.com/maps/@41.3686562,-89.0616738,15.74z)
Title: Re: What is the best interchange and why are they chosen?
Post by: kphoger on January 03, 2020, 09:56:21 PM
I'm partial to dogbones.
Title: Re: What is the best interchange and why are they chosen?
Post by: tolbs17 on January 03, 2020, 11:40:36 PM
Quote from: thspfc on January 03, 2020, 09:43:02 PM
I know cloverleaves suck, but they are aesthetically pleasing, like this one: https://www.google.com/maps/@41.3686562,-89.0616738,15.74z (https://www.google.com/maps/@41.3686562,-89.0616738,15.74z)
They are useful in rural areas though.