jlw (09/18/82)
f- Please excuse any prior null messages. I think I've got it right now I don't think that the first digit means anything special. For instance
jlw (09/18/82)
Once again please excuse the garbage articles. The first digit of circumferential interstate roads do not appear to have any meaning besides allowing for multiple intersecting interstates. Before I started researching this article in my Rand McNally Road Atlas I hadn't realized that these route numbers were reused. Example: I-95 north-south along the Eastern seaboard from Houlton, ME, to Miami, FL I-395 near Bangor, ME I-295 around Portland, ME I-495 around Boston, Mass (30-40 miles out) I-295 around Providence, RI I-295 around Trenton, NJ and then south toward Philadelphia I-195 east-west across NJ intersecting I-95 I-895 around Wilmington, Del I-695 the Baltimore, MD, Beltway I-495 near Washington, DC I-295 also Washington, DC I-295 around Richmond, VA I-br95 near Fayetteville, NC BTW, I'm sure that this little bit of interstate trivia has been mentioned before in netnews, what hasn't?, but odd numbered interstates run north and south while the even numbered ones are east-west. joe wood lime!ariel!jlw
johnl (09/18/82)
Interstate routes are numbered fairly rationally. East-west main
routes get even numbers less than 100 and north-south routes get odd
numbers less than 100. Numbers generally increase from southwest to
northeast so in San Diego there are routes 5 and 8, and here in Boston we
have 90, 93, and 95. Main long-distance routes get numbers that end in 0
and 5, so that 95 runs from Maine to Florida but 89 only goes from
Concord NH to Montreal.
For the three digit numbers, the first digit is even if it's a
bypass that comes back to the main highway and is odd if it's a spur.
The last two digits are the main route that it connects to. For example,
495 is a loop around Boston that connects to 95 at both ends, but 195 is
a spur from Providence out toward Cape Cod. Anomalies occur,
particularly in dense areas like New York, so don't write back to me with
counterexamples; these are general rules.
But basically, who cares?
John Levine, decvax!cca!ima!johnl, harpo!esquire!ima!johnl (uucp)
Levine@YALE (Arpa), 617-491-5450 (desperation)atlas1 (09/20/82)
Interstate Highway Numbering: I understand that "odd-hundred" interstates are branches off of a main highway that "dead end". "Even-hundred" numbers indicate routes which branch off of the main highway, but return to it later. Thus, Interstate 290 in Chicago goes around the city, while I-90 goes downtown; they meet on both the southeast side and the northwest side. I-394 branches off I-94, heads due South, and terminates in a cornfield. Tom Roberts ihuxf!atlas1
hjb (09/22/82)
even numbers run east-west with the numbers increasing from south to north (Interstate 10 Jacksonville FL to Los Angles, CA; Interstate 90 Boston, MA to Seattle, WA). Odd numbers run north-south increasing from west to east (Interstate 5 Belingham, WA to San Diego, CA; Inerstate 95 Houlton, ME to Miami, FL). If three digits are used and the first digit is even then the interstate circles (not always completely) around a metropolitan area, if the first digit is odd it is an access into the metropolitian area. Harry Benson
rra (09/27/82)
One aspect of the Interstate Highway numbering system not yet mentioned - In general, the numbers are (closely) the complement with respect to 100 or 110 of the US numbers used before the Interstate numbering system was founded back in Eisenhowers time. In the older system the numbers increased from north to south and east to west. So 40 was replaced by 70, 22 by 78, 1 by 95, 11 by 81 - The DoT had to do this to show the public that athey were realy' putting in new highways, and the Federal realy' putting in new highways, and the Federal Government supplied 90% of the funds. More important than the numbers is the lack of adequate maintenance of these "truck" highways. You can be sure that any of the roads put in early in the program will be in poor to very poor shape by now. and the newer roads will get poorer quickly. Richard Richard Anderson ariel!rra