1 vote

J Avenue Overpass


Oblique View

From the northeast side.

Photo taken by J.R. Manning

BH Photo #109484



Bridge is likely built using a former Chicago & North Western Railway span, which has been reconstructed for road use.


Pony truss bridge over Union Pacific Railroad on J Avenue
Boone County, Iowa
Open to traffic
Built 1900
- Chicago & North Western Railway (CNW)
- Union Pacific Railroad (UP)
Riveted double-intersection Warren pony truss
Length of largest span: 69.9 ft.
Total length: 140.1 ft.
Deck width: 18.4 ft.
Also called
Hump Bridge
Approximate latitude, longitude
+42.05213, -93.98946   (decimal degrees)
42°03'08" N, 93°59'22" W   (degrees°minutes'seconds")
Approximate UTM coordinates
15/418121/4656038 (zone/easting/northing)
Quadrangle map:
Boone West
Land survey
T. 84 N., R. 27 W., Sec. 27
Average daily traffic (as of 2007)
Inventory numbers
IA 77860 (Iowa bridge number)
BH 12908 (Bridgehunter.com ID)
Inspection report (as of May 2009)
Overall condition: Poor
Superstructure condition rating: Serious (3 out of 9)
Substructure condition rating: Poor (4 out of 9)
Deck condition rating: Poor (4 out of 9)
Sufficiency rating: 14.6 (out of 100)
View more at BridgeReports.com

Update Log 

  • February 25, 2017: New photos from Daniel Barnes
  • October 11, 2016: New photos from John Marvig
  • June 2, 2015: New photos from Kevin Skow
  • May 15, 2014: New photos from Lee Smith
  • March 28, 2013: New photos from John Marvig
  • September 2, 2011: Updated by Luke Harden: Added alternate name
  • February 19, 2010: Updated by J.R. Manning: Updated Location

Related Bridges 


  • J.R. Manning - thekitchenguy [at] sbcglobal [dot] net
  • Luke
  • John Marvig - marvigj27 [at] gmail [dot] com
  • Lee Smith - ljsmith_32 [at] hotmail [dot] com
  • Kevin Skow - weatherbum [at] hotmail [dot] com
  • Daniel Barnes


J Avenue Bridge
Posted May 6, 2013, by C J Johnson (108stitchesiowa [at] netzoola [dot] com)

Union Pacific trains roar many times daily under this bridge at well over 50+ mph before crossing the new concrete Kate Shelley High Bridge completed East of this bridge. I believe that this bridge is sometimes referred to as the "Humpback Bridge".

Photo taken Winter 2013.

UPRR Bridge
Posted July 16, 2007, by Lugnuts (thekitchenguy [at] sbcglobal [dot] net)

This bridge is located off 200th Street on L Road, a dead-end road, and provides the only access over the double-tracked Union Pacific mainline that some proptery owners have. The fence posts along the road leading away from the bridge appear to have been cut from a shoe tree.

This is a virtual twin to the pony truss bridge listed as #77840. The twin tracks shown continue west, cross the Des Moines River on the Kate Shelly Bridge (see Truss Bridge #77850 for more about the Kate Shelly Bridge) then curves to the southwest and goes under #77840.

The bridge is all wood timbered and wood decked. It has little trafic but appears to be well maintained.

Webmaster's note: The photos that were here have been incorporated into the main site.