??? I didn't think I-255 allowed bicycle traffic, being part of the interstate highway system. The IDOT bicycle safety maps lists 255 as "bicycle not allowed" roads. I wanted to use it to ride to Fosterburg IL, but they have those "No non-motorized vehicles or farm equipment allowed" signs posted.

Edit: Okay, so it is discouraged, but tolerated on the MO side. On Illinois side, it isn't tolerated, and bicyclists must get off at the first off ramp