The Mississippi River Bridge, La Crosse, WI

Cass Street Structure
• Structure ID:	B32030000000000.
• Highway:	Westbound US-14, Northbound US-61.
• Daily Traffic Count:	22,296 (2003)
• Bridge Type:	Steel Truss Through Deck.
• Length:	2,532 Feet Overall.
• Width:	30 Feet, 2 Lanes.
• Height Above Water:	67 Feet.
• Date Built:	Opened July 1940.

Cameron Avenue Structure
• Structure ID:	NBI B32020200020000.
• Highway:	Eastbound US-14, Southbound US-61.
• Daily Traffic Count:	19,800 (2003)
• Bridge Type:	Steel Arch Suspended Deck.
• Length:	2,573 Feet Overall, 475 Feet Longest Span.
• Width:	50 Feet, 2 Lanes.
• Height Above Water:	68 Feet.
• Date Built:	Opened November 17, 2004.

Statistics Common To Both Spans
• Location:	River Mile 697.5.
• River Elevation:	631 Feet.
• Navigation Channel Width:	462 Feet.

There are two bridges at this crossing. The older steel truss bridge is known as the Cass Street Structure. The new steel arch bridge was added in 2005. It is known as the Cameron Avenue Structure. Together, they are called The Mississippi River Bridge. The 87 foot tall arch for the Cameron Avenue bridge was built in a drydock downstream and floated into place. This allowed the main channel to remain open for shipping during construction. The Cass Street bridge is being rehabilitated during 2005 and 2006, with all traffic routed on the Cameron Avenue bridge during the project. When completed, the older bridge carries US-14 and US-61 west to Minnesota, while the newer bridge carries US-14 and US-61 traffic into downtown La Crosse.

The older bridge has a single entry in the National Bridges database. The newer bridge, however, has three entries. The approach spans are treated as seperate bridges from the arch section. The lengths and NBI numbers are:

West Approach: 1,110 Feet, NBI B32020200030000
Main Span: 475 Feet, NBI B32020200020000
East Approach: 1,010 Feet, NBI B32020200010000

Note that adding these three lengths ends up with a number that is longer than the officially reported length of the entire bridge project. I find these types of numerical discrepancies to be common.