IDOT has categorized all of the Circular Letters (CLs) issued, since the last manual revision in 1989, into three categories:
- Informational: These letters provide advisories to local agencies. Electronic copies of these letters area available on the Informational tab below.
- Valid: These letters revised the previous Bureau of Local Roads and Streets Manual issued in 1989. All of these CLs should be incorporated into the new BLRS Manual issued April 4, 2005. Electronic copies of these letters are available on the Valid tab below.
- Obsolete: The requirements in these letters no longer apply. Obsolete letters will not be available electronically. Please contact your district BLRS office for hard copies of these letters.