It seems the fluctuation in temperatures has increased recurring water infltration in the Lafontaine tunnel since it was built.
That's according to reports.
They add Transport Quebec has been trying to fix the problem for years.
Transport Quebec is reported saying there's no need to be concerned, that the problem does not affect the tunnel's structural integrity.
Major work on the tunnel is planned and could start in 2017.
The tunnel was built in 1967.