Beginning Wednesday, MoDOT will close the 1930s-era Fairfax Bridge for three weeks of emergency repairs.  This impacts the southbound lanes of US 69 between Platte and Wyandotte Counties.  Automobile traffic will be diverted to nearby I-635, but the closest bicycle crossing is Downtown on the Heart of America Bridge.  The northound lanes of US 69 will remain open on the adjacent Platte Purchase Bridge.

More info from MoDOT.