Interstate 70 - Auxiliary Routes

Auxiliary Routes

I-70 has one of the closest distances between two distinct child interstates with the same child interstate number. I-470 near Topeka, Kansas and I-470 on the east side of Kansas City, Missouri are approximately 72 miles (116 km) apart. This record is surpassed by I-291 around Hartford, Connecticut and I-291 near Springfield, Massachusetts which are unrelated, but are 23 miles (37 km) apart.

A breakdown of I-70's child routes follows:

• I-270 is a short connector between I-70 and I-25 in Denver, Colorado. It also carries U.S. 36 along its entire length.
• I-470 is a loop around the south side of Topeka, Kansas.
• I-670 is an alternate route of I-70 in Kansas City, Kansas and Kansas City, Missouri.
• I-470 is a connector between I-70 and I-435 in southeastern Kansas City and Independence, Missouri.
• I-170 is a connector between I-64 and I-270 in St. Louis County, Missouri.
• I-270 loops around St. Louis city and county. It is supplemented by I-255 to the east.
• I-270 is a beltway around Columbus, Ohio.
• I-670 is a 9.37 mile highway beginning at I-70 west of Downtown Columbus and terminating at I-270 in eastern Columbus that also provides direct access to Port Columbus International Airport from downtown.
• I-470 is a southern bypass around Wheeling, West Virginia.
• I-270 is a spur to Washington, D.C.. It was formerly designated I-70S.
• I-370 is a spur to Gaithersburg and Rockville, Maryland from I-270. It never connects to I-70.
• I-170 was to have been a spur into downtown Baltimore, Maryland, but the short part that opened never connected to I-70 or to any other Interstate Highway. It was decommissioned in 1989, and US 40 is the current designation for the freeway.