The problem has been dealt with analytically, numerically and experimentally. The problems of lateral instability and serviceability assessment have been analysed.

Lateral instability of a class of footbridges has been motivated modelling the footbridge as a parametrically excited system. Vibration serviceability assessment has been analysed in different loading scenarios: single resonant pedestrian, unrestricted pedestrian traffic, crowded conditions.

Closed-form expressions have been introduced for the dynamic response, which have been validated against numerical simulations and experimental measurements.

The experimental activity, carried out within research contracts, aimed at the dynamic identification of footbridges and at the evaluation of their vibration level in various pedestrian traffic conditions.