Superlatives

The records of the system.

Computed from the route data: the longest and shortest, the most-connected, and the oldest and newest designations among the active two-digit Interstates.

I-90Longest Interstate

Seattle to Boston.

3,204.6 mi

I-87Shortest two-digit

Raleigh area.

13.5 mi

I-95Most states crossed

Miami to Houlton.

16 states

I-95Most interstate junctions

Miami to Houlton.

14 junctions

I-70Earliest designation

Cove Fort to Baltimore.

1956

I-11Newest designation

Las Vegas region to northwestern Arizona.

2017

I-80Most auxiliary routes

San Francisco to Teaneck.

9 auxiliaries

Combined length of the active two-digit mainlines in this index: 42,637.5 miles.