Friday, January 18, 2008

Sometimes Texas is just in the way

In the original scheme, Interstate 10, 20, 30, 40, 70, 80, and 90, were intended to be the major west to east Interstate Highways. Of those seven, four (10, 20, 30, 40) cross parts of Texas. Of those four, two end in Texas -- 20 and 30. Two other of the main-route seven (70 and 80) cross parts of the former Republic of Texas.

Also in the original scheme, routes ending in "5" were the major south to north routes, such as 35 and 55. Of those routes, one (45) is entirely in Texas (Dallas to Galveston).

The Texas Highway Department designed the Interstate Highway shield and the Interstate system uses the Texas system of "Loops" (635) and "Spurs" (370).


David Amulet said...


I'd always heard that even-numbered interstates were (roughly) east-west and odd-numbered ones were (roughly) north-south. That would, of course, account for 5s as well as all other odd numbers, being north-south.

Four out of seven big E-W going through Texas is a great bit of geographical trivia. Thanks.

-- david

Jim said...

Davie -- the 'o's and '5's were to connect the major cities in a grid (in case of invasion) -- you're right about the odd/even directions, they were supposed to be diagonals (I-44, for example) or for routes that were using the 'connect the dots/cities' approach (I-55 from the Gulf thru STL to Chicago versus I-57 that misses STL).