Wireless Sensor Networks for Infrastructure Monitoring, TR-611, 2010

A good system of preventive bridge maintenance enhances the ability of engineers to manage and monitor bridge conditions, and take proper action at the right time. Traditionally infrastructure inspection is performed via infrequent periodical visual inspection in the field. Wireless sensor technology provides an alternative cost-effective approach for constant monitoring of infrastructures. Scientific data-acquisition systems make reliable structural measurements, even in inaccessible and harsh environments by using wireless sensors. With advances in sensor technology and availability of low cost integrated circuits, a wireless monitoring sensor network has been considered to be the new generation technology for structural health monitoring. The main goal of this project was to implement a wireless sensor network for monitoring the behavior and integrity of highway bridges. At the core of the system is a low-cost, low power wireless strain sensor node whose hardware design is optimized for structural monitoring applications. The key components of the systems are the control unit, sensors, software and communication capability. The extensive information developed for each of these areas has been used to design the system. The performance and reliability of the proposed wireless monitoring system is validated on a 34 feet span composite beam in slab bridge in Black Hawk County, Iowa. The micro strain data is successfully extracted from output-only response collected by the wireless monitoring system. The energy efficiency of the system was investigated to estimate the battery lifetime of the wireless sensor nodes. This report also documents system design, the method used for data acquisition, and system validation and field testing. Recommendations on further implementation of wireless sensor networks for long term monitoring are provided.

Road Safety Audit for County Road X-37, from the Intersection of G-62 to the East Corporate Limits of Columbus City in Louisa County, Iowa, 2009

A road safety audit was conducted for a 7.75 mile section of County Road X-37 in Louisa County, Iowa. In 2006, the average annual daily traffic on this roadway was found to be 680 vehicles per day. Using crash data from 2001 to 2007, the Iowa Department of Transportation (Iowa DOT) has identified this roadway as being in the highest 5% of local rural roads in Iowa for single-vehicle runoff- road crashes. Considering these safety data, the Louisa County Engineer requested that a road safety audit be conducted to identify areas of safety concerns and recommend low-cost mitigation to address those concerns. Staff and officials from the Iowa DOT, Governor’s Traffic Safety Bureau, Federal Highway Administration, Institute for Transportation, and local law enforcement and transportation agencies met to review crash data and discuss potential safety improvements to this segment of X-37. This report outlines the findings and recommendations of the road safety audit team to address the safety concerns on this X-37 corridor and explain several selected mitigation strategies.

Road Safety Audit for County Road W-55 in Washington County, Iowa, 2009

A road safety audit was conducted for a seven-mile section of County Road W-55 in Washington County, Iowa. In 2006, the average annual daily traffic on this roadway was found to be 1,290 vehicles per day. Using crash data from 2001 to 2007, the Iowa Department of Transportation (Iowa DOT) has identified this roadway as being in the top 5% of Iowa secondary rural roads with the highest density of serious (fatal and major injury) crashes for single-vehicle run-off-road incidents. Considering these safety data, the Washington County Engineer requested that a road safety audit be conducted to identify areas with safety concerns and to recommend low-cost mitigation to address those concerns. Staff and officials from the Iowa DOT, Iowa State Patrol, Governor’s Traffic Safety Bureau, Federal Highway Administration, Institute for Transportation, and local law enforcement and transportation agencies met to review crash data and discuss potential safety improvements to this segment of W-55. This report outlines the findings and recommendations of the road safety audit team to address the safety concerns on this W-55 corridor and explain several selected mitigation strategies.