AARoads Forum

National Boards => General Highway Talk => Topic started by: hotdogPi on April 16, 2014, 05:22:32 PM

Title: Interstate-standard surface roads
Post by: hotdogPi on April 16, 2014, 05:22:32 PM
Do any Interstate-standard surface roads exist?

I-587 would be an example, except the overpass makes it not a surface road.

There must be one somewhere. (It doesn't actually have to be an Interstate.)
Title: Re: Interstate-standard surface roads
Post by: agentsteel53 on April 16, 2014, 05:35:27 PM
you'd be looking for a road that doesn't intersect anything.  I suppose some very brief freeway spurs exist with this property.
Title: Re: Interstate-standard surface roads
Post by: getemngo on April 16, 2014, 06:06:18 PM
Or do you mean it meets all the requirements for lane width, median width, design speed, etc. and the only difference is that it does have intersections?
Title: Re: Interstate-standard surface roads
Post by: Pete from Boston on April 16, 2014, 10:38:12 PM
I don't understand -- is it a surface road if it is overpassed, but does not overpass anything else?
Title: Re: Interstate-standard surface roads
Post by: hotdogPi on April 16, 2014, 10:44:43 PM
Quote from: Pete from Boston on April 16, 2014, 10:38:12 PM
I don't understand -- is it a surface road if it is overpassed, but does not overpass anything else?

A surface road would have an intersection, not an overpass or underpass.

Since intersections would make it not Interstate standard, it can't cross any roads at all.
Title: Re: Interstate-standard surface roads
Post by: froggie on April 17, 2014, 06:14:03 AM
Quoteit can't cross any roads at all.

With this caveat, you just invalidated your own question.  There are numerous segments of freeway that meet your definition, but only in between adjacent overpasses or underpasses.

A MUCH-BETTER-QUESTION would be, what's the longest distance along a freeway between overpasses/underpasses/ramps.
Title: Re: Interstate-standard surface roads
Post by: Pete from Boston on April 17, 2014, 07:05:35 AM

Quote from: froggie on April 17, 2014, 06:14:03 AM
Quoteit can't cross any roads at all.

With this caveat, you just invalidated your own question.  There are numerous segments of freeway that meet your definition, but only in between adjacent overpasses or underpasses.

A MUCH-BETTER-QUESTION would be, what's the longest distance along a freeway between overpasses/underpasses/ramps.

Interstate standards would eliminate roads with stop signs, traffic lights, or left turns at either end.  So each end must be at some kind of RIRO situation, or the road can a) be an unfinished segment, or b) a closed loop (a racetrack, if you will, built to Interstate standards).

Title: Re: Interstate-standard surface roads
Post by: jeffandnicole on April 17, 2014, 11:09:32 AM
Quote from: Pete from Boston on April 17, 2014, 07:05:35 AM
b) a closed loop (a racetrack, if you will, built to Interstate standards).

In respect to curves, most racetracks aren't built to interstate standards either.  Interstate standards limit their banking on curves to 6% or so, depending on the region.  Racetracks are banked up to around 30%.
Title: Re: Interstate-standard surface roads
Post by: Pete from Boston on April 17, 2014, 12:49:35 PM

Quote from: jeffandnicole on April 17, 2014, 11:09:32 AM
Quote from: Pete from Boston on April 17, 2014, 07:05:35 AM
b) a closed loop (a racetrack, if you will, built to Interstate standards).

In respect to curves, most racetracks aren't built to interstate standards either.  Interstate standards limit their banking on curves to 6% or so, depending on the region.  Racetracks are banked up to around 30%.

Interstate standards require a relatively subdued race.  With no intersections, though, there's going to have to be some kind of crane to place the cars on the track.
Title: Re: Interstate-standard surface roads
Post by: Brandon on April 17, 2014, 01:07:16 PM
Quote from: Pete from Boston on April 17, 2014, 12:49:35 PM

Quote from: jeffandnicole on April 17, 2014, 11:09:32 AM
Quote from: Pete from Boston on April 17, 2014, 07:05:35 AM
b) a closed loop (a racetrack, if you will, built to Interstate standards).

In respect to curves, most racetracks aren't built to interstate standards either.  Interstate standards limit their banking on curves to 6% or so, depending on the region.  Racetracks are banked up to around 30%.

Interstate standards require a relatively subdued race.  With no intersections, though, there's going to have to be some kind of crane to place the cars on the track.

May I present to you the AASHO Test Loops.  These were interstate-standard loops built in the 1950s for testing pavement west of Ottawa, Illinois.  One still exists, the other is now a part of I-80.
Title: Re: Interstate-standard surface roads
Post by: vdeane on April 17, 2014, 01:32:00 PM
Quote from: Pete from Boston on April 17, 2014, 07:05:35 AM

Quote from: froggie on April 17, 2014, 06:14:03 AM
Quoteit can't cross any roads at all.

With this caveat, you just invalidated your own question.  There are numerous segments of freeway that meet your definition, but only in between adjacent overpasses or underpasses.

A MUCH-BETTER-QUESTION would be, what's the longest distance along a freeway between overpasses/underpasses/ramps.

Interstate standards would eliminate roads with stop signs, traffic lights, or left turns at either end.  So each end must be at some kind of RIRO situation, or the road can a) be an unfinished segment, or b) a closed loop (a racetrack, if you will, built to Interstate standards).


There are interstates that end at traffic lights.
Title: Re: Interstate-standard surface roads
Post by: Alps on April 17, 2014, 06:09:08 PM
I don't see this topic going anywhere. You want a divided highway with no driveways for some distance without there being any grade separations. There are many such scenarios - US highways in the mountains in the West, for example, have such segments. In urban areas, though, what can you expect to possibly find? I-587 ends at a circle and a traffic light. So right there, you allow each segment to end at a traffic light. Fine, JFK Parkway (Livingston, NJ) between CR 510 and West Hobart Gap Road.
Title: Re: Interstate-standard surface roads
Post by: agentsteel53 on April 17, 2014, 06:20:54 PM
Quote from: Alps on April 17, 2014, 06:09:08 PM
US highways in the mountains in the West, for example, have such segments.

are many divided?  offhand I can think of US-395, and that has crossings every mile or so, and the occasional single-sided (likely minimally improved dirt) driveway access maybe 3x as frequently.