Feds Cite 45 Problematic Bridges In Navajo County

Click on the map to see problematic bridges in Arizona, as rated by the Federal Highway Administration. Zoom in to see bridges in Navajo County. Problematic bridges are rated “structurally deficient” (blue), which means they have a significant defect, or “functionally obsolete” (red), which means they are too small or not suited for modern traffic.

Forty-five Navajo County bridges are included in recent Federal Highway Administration (FHA) statistics that label nearly 1,000 bridges in Arizona as problematic.

According to the 2014 National Bridge Inventory (NBI) Database, Arizona has 8,035 highway bridges. Of those, 256 are considered structurally deficient and 684 are functionally obsolete.

A structurally deficient bridge has one or more significant defects that require attention. This does not indicate the severity of the defect, but simply that one is present. A functionally obsolete bridge may be perfectly safe and structurally sound, but its small size may cause traffic jams, lack enough height clearance for oversized vehicles or have insufficient space for emergency shoulder lanes.

The government defines its Sufficiency Rating as the truest measure of a bridge’s overall fitness based on factors culled from more than 20 NBI data measurements, including fields that describe its structural integrity, functional end of life and usefulness to the public.

Based on a 100-point scale, the result is a rating in which 100 percent would be the score of a fully sufficient bridge, while zero percent would indicate a fully insufficient or deficient bridge.

NBI records show that the recently collapsed Tex Wash Bridge along Interstate 10 in California was rated functionally obsolete. However, inspectors reported that excessive rainwater runoff eroded one of the bridge’s embankments, leading to the collapse of its eastbound span on July 19.

More than 150 bridges in Arizona scored below a rating of 50 in 2014. Of Navajo County’s 298 bridges, 25 were considered structurally deficient and 20 were rated functionally obsolete. At least 21 of these are located along the I-40 corridor.

Arizona Department of Transportation (ADOT) Holbrook District Engineer Lynn Johnson is managing the current rehabilitation of the Leroux Wash Bridge along the I-40 corridor between Holbrook and Joseph City, which was rated as structurally deficient last year. Johnson said the ADOT roads management team prioritized the repair of this bridge in line with FHA guidelines.

“Typically, ADOT bridge crews inspect every bridge structure within the state every two years, and we schedule repairs based on priority statewide. The Leroux Wash bridge in Holbrook had a deck structure they were concerned about, so we removed the surface asphalt and replaced the deck,” he explained.

Johnson noted that several other Holbrook area bridges are slated for preservation and repair in the near future.

“We’re on track to replace the eastbound bridge at Tanner Wash on I-40 next to the power plant at Cholla in the spring of 2016, weather permitting; we replaced its westbound bridge two or three years ago. And we’re just finishing the Five Mile Draw Bridge in Snowflake this week. We will begin deck replacement of the SR-87 bridge in Winslow beginning the first week in August. We also have a few upcoming bridge projects scheduled on AZ-264 in the Navajo Nation,” he said.