THE ECONOMICS OF INTEGRATING INNOVATIVE MONITORING TECHNOLOGIES INTO BRIDGE MANAGEMENT POLICY
Presumed structurally deficient bridges may deserve a second chance. In this study, three management policies incorporating innovative monitoring schemes were investigated using an exploratory economic model. The model focused on decisions regarding bridges that were diagnosed as structurally deficient through visual inspections (VI). Three policies were considered: Policy I was to rebuild the bridge, while Policies II and III used various testing and monitoring schemes to determine if the bridge is actually structurally deficient and in need of replacement. Load rating tests (LRT) and structural health monitoring (SHM) were incorporated into Policy II. Policy III supplemented LRT and SHM with an additional low-cost testing method referred to as the digital signature (DS), which measures the deflection profile of the bridge. The results of this exploratory economic model show that for a fleet of 100 bridges, there is a major economic benefit if Policy II is used over Policy I. The results showed further savings using Policy III if DS testing is at least 50% accurate. DS testing is relatively inexpensive and can therefore reduce the overall costs by adding another layer of testing between VI and monitoring. Policy III allows bridge managers to have a truly hybrid approach to bridge asset management. Overall, the economic benefits provide an impetus for monitoring bridge networks to confirm and supplement inspection results.