Talk:Interstate Highway standards

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Minimum Median?[edit]

This article explains that interstates must have a minimum median wisth of 22 feet - however, in any major metro area or when the interstate passes through a narrow area like a canyon, the opposing directions of the highway are divided by nothing more than a k-rail. Should there be a notation in there somewhere noting this? - Hobgoblin

I believe (but am not sure) that those cases do not meet standards. In many or most cases, they were built before the current standards, so are grandfathered in. But if major reconstruction is done in those places, the median will have to be widened or the state will have to get an FHWA waiver. --SPUI (talk) 23:38, 23 Feb 2005 (UTC)

My understanding is that the minimum median was to be 24 feet, to allow two extra lanes in the future. 60.229.0.220 (talk) 10:18, 13 September 2012 (UTC)[reply]

Sharp curves[edit]

I read articles about Michigan State Highway 14 not meeting Interstate standards due to sharp curves on the corridor, the sharpness of curves should be mentioned in this article. --SuperDude 23:57, 14 May 2005 (UTC)[reply]

That's part of the design speed. --SPUI (talk) 00:28, 15 May 2005 (UTC)[reply]
I'm curious as to what the specs of the car used to define what is safe are given that some cars have a tighter turning radius than others. (curves) In addition some cars have better brakes. (downhill, especally when combined with curves) Jon (talk) 22:54, 27 November 2007 (UTC)[reply]
Jon, I think they probably base it on the vehicles that make the widest turns, or the vehicles that have the worst brakes. If they based it on the worst cars, the better ones would be covered. If they based it on the best cars, the other cars wouldn't be covered. — Preceding unsigned comment added by 68.33.242.8 (talk) 20:15, 31 May 2013 (UTC)[reply]

Measurement Units[edit]

Why are the primary units of measurement metric (meters), with the actual standard and local system (feet) in parentheses? This results in odd figures given, with nice round numbers in parens. While I am a metric fan, surely the measurement system in the locality should be the primary. The locality here is clear and undisputable.

human 00:53, 11 December 2005 (UTC)[reply]

Agreed. I have swapped all the measurements. Nohat 22:03, 7 January 2006 (UTC)[reply]
AASHTO uses metric first, though many (most?) states don't for design. --SPUI (talk - don't use sorted stub templates!) 17:05, 7 March 2006 (UTC)[reply]

Myth about 1/5 miles required to be straight untrue.[edit]

I think it would be a pretty good idea to include a statement which refutes the fact that one out of every five miles on an interstate must be straight. It is a popular urban legend that Eisenhower mandated one out of every five miles on a highway must be straight; I beleive this beleif is popular enough to warrent inclusion at the end of the article or something. Here is a link as evidence:

http://www.fhwa.dot.gov/infrastructure/rw00b.htm

That's in Interstate Highway System. --SPUI (talk - don't use sorted stub templates!) 17:05, 7 March 2006 (UTC)[reply]
Considering this piece of information in the article you mentioned is in the Standards section, which links to this as the main article, I think it should be placed within this article. —Onore Baka Sama(speak | stalk) 17:13, 17 August 2010 (UTC)[reply]

I totally agree. It's an extremely widespread misconception. —Preceding unsigned comment added by 76.190.151.109 (talk) 01:17, 29 June 2008 (UTC)[reply]

The original rumour was that it was to provide emergency landing for aeroplanes. This is of course not true, but it is more believable than simply "Eisenhower mandated" it. 60.229.0.220 (talk) 10:20, 13 September 2012 (UTC)[reply]

US Code[edit]

23 USC section 109:

Note about United States[edit]

Besides the word "American" mentioned as part of the name of the agency in charge, there is no note of location. Can we add a note making it clear this applies to the United States of America only?

I added "in the United States" to the introduction. I think that's clear enough. Jpp42 13:18, 20 May 2007 (UTC)[reply]

Did I just miss it? No mention of signage being white of green???[edit]

Did I miss it? Doesn't the signage also have to be white letters on Green background for directional signs? CaribDigita (talk) 01:33, 18 March 2009 (UTC)[reply]

Signage is not an Interstate standard issue per se. It is addressed in the Manual of Uniform Traffic Control Devices, which covers all roads. Brian Powell (talk) 03:38, 19 March 2009 (UTC)[reply]

Vertical Clearance.[edit]

In the initial specification, the vertical clearance was a fairly arbitrary number. Shortly after this, however, it was raised slightly to a particular value that I don't recall, but it was for a purpose. Since the IHS is in fact Interstate AND DEFENCE Highways, it was to ensure that a particular kind of missile on its carrier (Minuteman?????) could be transported everywhere along the system. 60.229.0.220 (talk) 10:23, 13 September 2012 (UTC)[reply]

Maximum Grade.[edit]

There is a second part to this. If the maximum grade uphill exceeds 1:X, then an additional climbing lane is to be provided. Ditto for the maximum grade downhill - if greater than 1:Y then another lane. From memory, X==16 and Y==10. 60.229.0.220 (talk) 10:25, 13 September 2012 (UTC)[reply]

overly technical?[edit]

it really doesn't seem very technical to me, and actually pretty understandable. Aunva6 (talk) 09:29, 23 February 2013 (UTC)[reply]

Note in the banner states: Many terms, such as "clear zone" and "recovery area", are used that don't have explanations; many of these are red links, which are particularly unhelpful.
I added a wikilink for "clear zone," not 100% sure that this is what they are talking about in the banner. I'll look for "recovery area" next. CounterEarth (talk) 19:40, 29 April 2021 (UTC)[reply]
I agree, on the whole it seems appropriatly technical for such a niche article. Benjiman678 (talk) 05:01, 29 December 2023 (UTC)[reply]

Template signs in this article[edit]

The accompanying text says "(left)" and "(right)", but what would be correct, at least for my tablet, is "(top)" and "(bottom)". Carlm0404 (talk) 18:33, 26 September 2018 (UTC)[reply]

2016 Standards[edit]

The standards were revised in 2016, and I have updated the article accordingly. 2600:1700:F0C0:CF0:1820:38B3:9EF4:3AF (talk) 06:41, 12 August 2019 (UTC)[reply]