Interstate 170
| Inner Belt Expressway | ||||
I-170 highlighted in red | ||||
| Route information | ||||
| Auxiliary route of I-70 | ||||
| Maintained by MoDOT | ||||
| Length | 11.17 mi (17.98 km) | |||
| Existed | 1956–present | |||
| NHS | Entire route | |||
| Major junctions | ||||
| South end | I-64 / US 40 in Richmond Heights | |||
| I-70 in Berkeley | ||||
| North end | I-270 in Hazelwood | |||
| Location | ||||
| Country | United States | |||
| State | Missouri | |||
| Counties | St. Louis | |||
| Highway system | ||||
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Interstate 170 (I-170), also known as the Inner Belt Expressway, is an 11.17-mile (17.98 km) north–south auxiliary Interstate Highway in Greater St. Louis, Missouri. I-170 connects to I-270 at its northern terminus and I-64 at its southern terminus. I-170 crosses its parent, I-70, near St. Louis Lambert International Airport.