US Interstate System marks 50th Anniversary
// September 2nd, 2006 // 1 Comment » // Travel
I am fascinated with the interstate system in the US. Today’s topic devoted to the 50th anniversary of something we take for granted, but would be in rough shape without.
June 29th marked the 50th anniversary of the US Interstate System. Imagine the country without it. In 1919, Dwight Eisenhower took a trip with his Army convoy across the country. Details of this 62 day adventure across 3000 miles of dirt roads, wagon trails, and unpassable rivers would later “pave the way” for him to sign the Federal-Aid Highway Act of 1956 into law as President, ultimately providing the needed funds to begin the project in earnest.
The interstate system was originally designed to assist in the national defense by connecting major metropolitan cities and regions with eachother. During the debates, he was met with opposition fighting from Environmentalists who perhaps didn’t want the pristine countryside tainted with traffic. Or perhaps it was the idea that it would be for defense. Sounds kind of similar to what we are facing today with the oil mess we are in. Why not do something for the good of the country and allow for some exploration in places that few will ever see anyway.
Some neat facts about the system.
Interstate Route Numbering System - Major Interstate routes are designated by one- or two-digit numbers. Routes with odd numbers run north and south, while even numbered run east and west. For north-south routes, the lowest numbers begin in the west, while the lowest numbered east-west routes are in the south. By this method, Interstate Route 5 (I-5) runs north-south along the west coast, while I-10 lies east-west along the southern border.
In two cases, a major route has two parallel or diverging branches. In those cases, each branch is given the designation of the main route, followed by a letter indicating a cardinal direction of travel (east, west, etc). In Texas, for example, I-35 splits at Hillsboro, with I-35E going through Dallas, while I-35W goes through Fort Worth. The two branches merge at Denton to reform I-35. A similar situation exists along I-35 in the Minneapolis-St. Paul area of Minnesota.
The major route numbers generally traverse urban areas on the path of the major traffic stream. Generally, this major traffic stream will be the shortest and most direct line of travel. Connecting Interstate routes and full or partial circumferential beltways around or within urban areas carry a three-digit number. These routes are designated with the number of the main route and an even-numbered prefix. Supplemental radial and spur routes, connecting with the main route at one end, also carry a three-digit number, using the number of the main route with an odd-number prefix.
To prevent duplication within a State, a progression of prefixes is used for the three-digit numbers. For example, if I-80 runs through three cities in a State, circumferential routes around these cities would be numbered as I-280, I-480, and I-680. The same system would be used for spur routes into the three cities, with routes being numbered I-180, I-380, and I-580, respectively. This system is not carried across State lines. As a result, several cities in different States along I-80 may each have circumferential beltways numbered as I-280 or spur routes numbered as I-180.
Interstate Exit Numbers - The States typically use one of two methods of numbering the Interstate interchange exits.
- The Consecutive numbering system — Starting at the most westerly or southerly point on each Interstate route, interchanges are numbered consecutively. Thus the first interchange becomes Interchange #1. Each succeeding interchange is numbered consecutively as #2, 3, 4, etc.
- The Milepost numbering system — All Interstate routes are mileposted beginning at the most westerly or southerly point. The beginning point is milepost ‘0′. If the first interchange on the route is located between milepost 4.0 and 5.0, it is numbered as Interchange #4. The next interchange, if located at milepost 8.7, would be numbered as Interchange #8, etc. With this system the motorist can easily determine the location and distance to a desired interchange.
Longest East-West Route - I-90 from Boston to Seattle: 3,020.54 miles
Longest North-South Route - I-95 from Houlton, ME to Miami, FL: 1,919.74 miles
State with the Most Interstate Miles - Texas has 17 routes covering 3,233.45 miles
State with the Most Interstate Routes - New York has 29 routes covering 1,674.73 miles
Interstate Route Which Traverses the Most States - I-95, which travels through 16 States (FL,GA,SC,NC,VA,DC,MD,DE,PA,NJ,NY,CT,RI,MA,NH,ME)
For more info on the Eisenhower Interstate System, go HERE.
