Traffic crossing the Forth Road Bridge dropped by almost 50,000 vehicles last month, new figures show.
Corrosion has been found in the bridge's main suspension cables
The decrease was attributed to the poor weather and the public sector workers' strike for the dip in numbers.
However, even with estimated traffic levels on the strike day included, March's figures would have remained the lowest since 2002.
A total of 952,963 vehicles paid tolls to travel between Edinburgh and Fife throughout March.
Despite warnings that increasing traffic is crippling the ageing crossing, the annual number of cars and lorries travelling over the Firth of Forth has not risen since 2003.
However the bridge is still carrying twice its design capacity - resulting in corrosion in the main suspension cables.
Alastair Andrew, general manager and bridgemaster for the Forth Estuary Transport Authority (Feta), said: "We are confident that by being proactive in our investigations we have caught the corrosion at a time when we can now do something about it."
Mr Andrew said: "It would be nice to think that traffic congestion was on the way down, but all the long-term trends point to continued traffic growth.
"What's more, our detailed statistics show the number of HGVs crossing the bridge rising by 5.6%."
John McGoldrick, coordinator of the National Alliance Against Tolls Scotland, said the reasons for the traffic fall was "more spin from the authorities".
He added: "The authorities are desperate to try and justify keeping tolls.
"An imposition which is condemned by Fife Council and by people and businesses. No one wants the tolls except for the bridge authority and the Scottish Executive."