Editing Bridge (section)

==Bridge maintenance==
[[File:Example HiFIT-treated assembly.jpg|thumb|A highway bridge treated with [[high-frequency impact treatment]]]]
The estimated life of bridges varies between 25 and 80 years depending on location and material.<ref>{{Cite journal|last1=Estes|first1=Allen C.|last2=Frangopol|first2=Dan M.|date=1 December 2001|title=Bridge Lifetime System Reliability under Multiple Limit States|url=http://ascelibrary.org/doi/10.1061/%28ASCE%291084-0702%282001%296%3A6%28523%29|journal=Journal of Bridge Engineering|language=en|volume=6|issue=6|pages=523–528|doi=10.1061/(ASCE)1084-0702(2001)6:6(523)|issn=1084-0702}}</ref><ref name=":12">{{Cite book|last1=Ford|first1= K.|last2= Arman|first2= M.|last3 = Labi|first3= S.|last4= Sinha|first4= K.C.|last5= Thompson|first5 = P.D.|last6= Shirole|first6 = A.M.|last7= Li|first7 = Z.|date = 2012|id= NCHRP Report 713 |title = Estimating life expectancies of highway assets|publisher = Transportation Research Board, National Academy of Sciences|location = Washington, DC}}</ref>

Bridges may age hundred years with proper maintenance and rehabilitation. Bridge maintenance consisting of a combination of structural health monitoring and testing. This is regulated in country-specific engineer standards and includes an ongoing monitoring every three to six months, a simple test or inspection every two to three years and a major inspection every six to ten years. In Europe, the cost of maintenance is considerable<ref name=":1">{{Cite journal|last1=Žnidarič|first1=Aleš|last2=Pakrashi|first2=Vikram|last3=O'Brien|first3=Eugene|last4=O'Connor|first4=Alan|s2cid=110344262|date=December 2011|title=A review of road structure data in six European countries|journal=Proceedings of the Institution of Civil Engineers - Urban Design and Planning|volume=164|issue=4|pages=225–232|doi=10.1680/udap.900054|issn=1755-0793|hdl=10197/4877|hdl-access=free}}</ref> and is higher in some countries than spending on new bridges. The lifetime of welded steel bridges can be significantly extended by [[High Frequency Impact Treatment|aftertreatment of the weld transitions]]. This results in a potential high benefit, using existing bridges far beyond the planned lifetime.