# Waivers to US federal highway regulations **URL:** \ **Category:** Factual Questions\ **Created:** [August 14, 2001, 3:34am UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145 "2001-08-14T03:34:48Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![evilhanz](https://avatars.discourse-cdn.com/v4/letter/e/ba8739/32.png) [@evilhanz](https://boards.straightdope.com/u/evilhanz)\ **Post date:** [August 14, 2001, 3:34am UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145/1 "2001-08-14T03:34:48Z")
When interstate highways are built with federal funds, it is my understanding that the construction must adhere to strict federal engineering guidelines - width of roadbed, grade, curvature, speed limits, separation of lanes of travel, and such. In the history of the interstate system only two road segments that I know of have been granted waivers to these rules: 1) I-70 through Glenwood Canyon in Colorado, and 2) I-93 through Franconia Notch in New Hampshire. I am only familiar with I-93 where the highway becomes an undivided parkway dropping from two lanes in each direction to one. The speed limit also drops from 65 mph to 45 mph. My questions are: 1. Where can I obtain a copy of the engineering guidelines governing interstate highway construction? 2. How do states apply for waivers and what qualifications must be met? I know that I-93 got a waiver in large part to preserve the unique character and historic locations within the notch. Surely there must be more specific rules. 3. Have any other waivers been granted? What waiver applications have been denied in the past? 4. On what basis did I-70 in Glenwood receive a waiver? ---
**Author:** ![MrDeath](https://avatars.discourse-cdn.com/v4/letter/m/22d042/32.png) [@MrDeath](https://boards.straightdope.com/u/MrDeath)\ **Post date:** [August 14, 2001, 5:07am UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145/2 "2001-08-14T05:07:37Z")
Huh? (1) Glenwood Canyon’s [spanking new I-70](http://arts.endow.gov/endownews/news00/feddesign/feddesign14.html), completed in 1993 at a cost of $40 million per mile, was the last major link to be completed in the Interstate highway system, and AFAIK meets all the criteria for an Interstate (see below). (2) All the maps I can find on the Web, [including this one](http://homepage.fcgnetworks.net/lkport/page4.htm), show that the Franconia Notch Parkway is decidedly _not_ part of I-93; it is U.S. Highway 3 and it connects two _sections_ of I-93. You can obtain a copy of “A Policy on Design Standards - Interstate System” (publication code D-4) for $12.00 at the [AASHTO bookstore](https://www.transportation.org/publications/bookstore.nsf/), if you’re morbidly curious. You might also find [this DOT page](http://www.fhwa.dot.gov/infrastructure/progadmin/Interstate.html) to be useful. It provides some basic standards that Interstates have to meet: > [@](#): > > Examples of design standards for the Interstate System include full control of access, design speeds of 50 to 70 miles per hour (depending on type of terrain), a minimum of two travel lanes in each direction, 12-foot lane widths, 10-foot right paved shoulder, and 4-foot left paved shoulder. It also states that, as of the end of 1998, > [@](#): > > all but 7.60 miles of the 42,794-mile Interstate System as designated under former Sections 103(e)(1), (2), or (3) of Title 23 were completed and open to traffic. This includes two sections in Ohio and one each in CA, DC, MA and PA. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [August 14, 2001, 7:32am UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145/3 "2001-08-14T07:32:06Z")
> [@](#): > > (2) All the maps I can find on the Web, including this one, show that the Franconia Notch Parkway is decidedly not part of I-93; it is U.S. Highway 3 and it connects two sections of I-93. Frankly, I can’t tell anything by that map. My DeLorme Atlas of New Hampshrie shows that I-93 and U.S. Route 3 are the same road through the notch. [This page](http://www.aaroads.com/roadtrips/vermont/franconia-01.html) has a photograph of the signage to prove it. [See also this map](http://mapserver.maptech.com/homepage/index.cfm?lat=44.1387&lon=-71.68&scale=100000&zoom=100&type=1&icon=0) ---
**Author:** ![evilhanz](https://avatars.discourse-cdn.com/v4/letter/e/ba8739/32.png) [@evilhanz](https://boards.straightdope.com/u/evilhanz)\ **Post date:** [August 14, 2001, 2:55pm UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145/4 "2001-08-14T14:55:03Z")
I-93 and Route 3 coincide for the trip through the notch. I-93 was overlaid on the path of the older State Route 3 when it was constructed through the notch in the 1980’s. On local maps this difference is shown subtly, using the interstate highway graphic through notch with the standard state route graphic ont eh outside. The map you linked to is a poor representation. I travel through the area routinely, and I can assure you that these details are accurate. Besides, I just finshed doing some research on the construction AND watched a documentary on the subject. (I’m a bit of a history buff on the region). As to Glenwood Canyon, it’s waiver was mentioned in the documentary I saw about Franconia Notch demonstrating the difficulties involved in deviating from the standard on federal highway projects. Later, I spoke with a park ranger about Glenwood Canyon. He didn’t know the specific details of the waiver, but confirmed that it too had special project considerations. After doing some research on the internet I believe I-70 deviates from the spec on curvature and the narrow width of its roadbed. In fact, warning systems have been installed to alert drivers about these severe driving conditions due to abnormally high incidences of rollovers. There is some information about this in the Nov/Dec 97 issue of [Public Roads Online](http://198.252.9.108/govper/PublicRoads/NovDec97.pdf). I don’t know how the hanging bridges and the tunnels affect I-70’s status since I haven’t read the specifications yet. ---
**Author:** ![Tedster](https://avatars.discourse-cdn.com/v4/letter/t/4491bb/32.png) [@Tedster](https://boards.straightdope.com/u/Tedster)\ **Post date:** [August 14, 2001, 2:59pm UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145/5 "2001-08-14T14:59:06Z")
Glenwood canyon was _scary_ before the interstate was completed. It’s still pretty curvy, but lotso fun on a bike or sports car. ---
**Author:** ![MrDeath](https://avatars.discourse-cdn.com/v4/letter/m/22d042/32.png) [@MrDeath](https://boards.straightdope.com/u/MrDeath)\ **Post date:** [August 15, 2001, 12:25am UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145/6 "2001-08-15T00:25:05Z")
A little sleuthing gives us: [A section of I-10](http://www.ihoz.com/I10.html) with exits onto people’s driveways; [a spur route (I-180)](http://www.ihoz.com/I80.html) with _traffic lights!_; and [a section of I-90](http://www.ihoz.com/I90.html) near the MT-ID border that is not divided. Each of these is in violation of one of the interstate standards (full control of access, minimum driving speed, and left shoulder respectively). ---
**Author:** ![Montfort](https://avatars.discourse-cdn.com/v4/letter/m/d6d6ee/32.png) [@Montfort](https://boards.straightdope.com/u/Montfort)\ **Post date:** [August 15, 2001, 12:37am UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145/7 "2001-08-15T00:37:16Z")
> [@](#): > > \*Originally posted by MrDeath \* > **A little sleuthing gives us: > [A section of I-10](http://www.ihoz.com/I10.html) with exits onto people’s driveways;** I’ve driven the whole of I-10, and I don’t recall seeing any exits like that, nor on the page you link to. What are you talking about? Or, was I too bored driving all 879 miles in Texas to notice this? ---
**Author:** ![MrDeath](https://avatars.discourse-cdn.com/v4/letter/m/22d042/32.png) [@MrDeath](https://boards.straightdope.com/u/MrDeath)\ **Post date:** [August 15, 2001, 1:06am UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145/8 "2001-08-15T01:06:33Z")
> [@](#): > > \*Originally posted by Montfort \* > \*\* > > > [@](#): > > > > \*Originally posted by MrDeath \* > > **[A section of I-10](http://www.ihoz.com/I10.html) with exits onto people’s driveways;** > > I’ve driven the whole of I-10, and I don’t recall seeing any exits like that, nor on the page you link to.\*\* From the page I linked to: > [@](#): > > I-10 is so isolated that they allowed at grade crossings for people’s driveways there. ---
**Author:** ![Montfort](https://avatars.discourse-cdn.com/v4/letter/m/d6d6ee/32.png) [@Montfort](https://boards.straightdope.com/u/Montfort)\ **Post date:** [August 15, 2001, 3:32am UTC](https://boards.straightdope.com/t/waivers-to-us-federal-highway-regulations/76145/9 "2001-08-15T03:32:29Z")
D’oh! I missed that. I must’ve zoned out reminiscing about my drive across I-10.