ABSTRACT
The dimensioning philosophy adopted when writing new bridge codes and consequently when designing new structures, is conservative in nature. The traffic load models of these codes need to cover all European conditions and cater for future heavier traffic. Despite this, these traffic load models are often used to evaluate existing infrastructure where the actual traffic conditions can be vastly different from those assumed by the code writers. This conservative philosophy should be abandoned when assessing existing bridges as replacement cost or strengthening cost may be extremely expensive.
