The four state capitals not directly served by the Interstate System are:
- Juneau, Alaska
Jefferson City, Missouri
Pierre, South Dakota
Missouri, Kansas, and Pennsylvania have claimed the title of first Interstate Highway. On August 13, 1956, Missouri was awarded the first contract under the Federal Aid Highway Act of 1956. Kansas says road paving started September 26, 1956. On October 1, 1940, 162 miles of the Pennsylvania Turnpike now designated I‑70 and I‑76 opened between Irwin and Carlisle.
Carson City, Nevada is the most recent state capital to become directly served by the Interstate System. The new I-580 freeway between Reno and Carson City running north and south opened in August 2012.
Just in- Nevada's construction on the southern half of the Fairview Drive interchange and the South Carson Street interchange, as well as roadway paving, landscaping, signing, pavement striping, and sound wall, signal, and lighting installation is expected to begin 2015 - 2016. The I-580/U.S. 395 Carson City Freeway Project is expected to be completed 2017 -2018.