Existing bridges, either aged or partly damaged structures, are sensitive to heavy traffic loads. These loads may be highly but legally loaded vehicles within the common weight limits, authorized abnormal loads, or illegally overloaded vehicles. Some of these heavy vehicles may cross bridges above their loading capacity, inducing either light or severe damages, or even bridge collapse, with potential injuries or fatalities. Crossing a posted bridge above the limit is an infringement, but with relatively low penalties with respect to the potential consequences for the bridge and its users. Repairing or rebuilding a severely damaged bridge is very costly, and a long bridge closure has a high economical cost. Most of the developed or LMIs countries worldwide are facing issues with bridges exposed to and damaged by highly loaded heavy commercial vehicles (HCVs).

The session will assess and discuss the impacts and consequences of high (over)loads of HGVs on road infrastructures, mainly pavements and bridges, and on traffic safety and management. It will also review the mitigation solutions proposed or implemented in PIARC countries to avoid severe overloading cases and to protect the road asset, including (over)loads monitoring by WIM (Weigh-in-Motion) systems and IAP strategies, as well as pavement and bridge instrumentation and monitoring.