Here's something for Iowa: A study on extending the partial beltway of Des Moines north of I-80 back to I-35:
http://www.polkcountyiowa.gov/publicworks/Pages/neBeltway.aspx (http://www.polkcountyiowa.gov/publicworks/Pages/neBeltway.aspx)
Alternative alignments map:
http://www.polkcountyiowa.gov/publicworks/PDFs/NEBeltwayAlternateRoutes.pdf (http://www.polkcountyiowa.gov/publicworks/PDFs/NEBeltwayAlternateRoutes.pdf)