Vibrations are discussed as being especially harmful to historic buildings because of structural deterioration resulting from age. The effects of traffic vibration depend on the source, the transmission path, and the condition of the affected structure. Remedial action may include: changing the road surface, influencing the transmission path and reinforcing the structure. Long term effect of vibration can include material fatigue and foundation settlement. Sonic boom caused by supersonic air traffic can also cause damage. Further research is proposed to determine the in situ strength of historic structures; methods must be developed for strengthening to prevent the detrimental effects of vibration.