Interstate 35 also splits into I-35W and I-35E in the Twin Cities. These are the only two places in the Interstate system where that happens; all others have been decomissioned.
The Twin Cities Interstates are also interesting in that the ring road is split into two numbers--I-494 and I-694. They share a common origin for the mile markers, near the Minneapolis-St. Paul International Airport.
Also, Read Your Road has moved to http://safety.fhwa.dot.gov/media/ryr.htm .