As the number of bridges requiring rehabilitation increases, engineers are faced more frequently with the decision on whether to close a bridge to traffic while repairs are carried out. Most agencies maintain traffic on a deck during construction of a concrete overlay or widening, although several impose speed and weight restrictions on vehicles. Vehicles cause bridges to vibrate which in turn can be detrimental to fresh concrete repairs and overlays thereby increasing maintenance costs. Although overlays appear vulnerable to cracking and debonding under the action of traffic induced vibrations, none of the identified defects has been found to be attributable to traffic on the deck at the time of construction.  The report for this topic can be purchased at https://www.trb.org/news/blurb_detail.asp?id=3471