Southbound Mercier Bridge closed for entire summer
The southbound span of the Mercier Bridge will remain closed for the entire summer because of the recent discovery of structural damage, but most commuters should be unaffected by the closure.
Starting Wednesday and continuing throughout the summer, the northbound span of the bridge will allow only for one-way traffic on weekdays. Traffic will flow towards the island from midnight to noon, and will flow off the island from noon to midnight.
But the same number of lanes that were available to those commuters before will still be available to them now. The ones that will be inconvenienced are those who usually go against the normal flow of traffic.
On weekends the bridge will permit one lane of traffic in and out of Montreal.
"We will change traffic flow to being one lane in each direction," said Anne-Marie Leclerc with the Ministry of Transportation.
"There will also be extra tow trucks and emergency crews on hand to quickly deal with any accident."
The provincial government hopes the bridge will reopen before school begins in August, but it is possible the bridge will only reopen to traffic in September.
Provincial Transport Minister Sam Hamad made the announcement Wednesday, 14 hours after half of the bridge was closed because of newly-discovered structural weaknesses.
"The Mercier Bridge was built in 1930," Hamad explained. "So 80 years after, we need some work on that. It's normal."
However, Hamad assured drivers that using the more recently built northbound side of the bridge poses absolutely no danger to drivers.
Drivers heading toward Chateauguay or Kahnawake were surprised Tuesday night by the sudden closure, and it had a ripple effect on Wednesday morning's rush hour for drivers coming from the West Island into the downtown core of Montreal.
However, Wednesday afternoon's rush hour was relatively normal at the Mercier Bridge as several commuters appeared to want to steer clear of the potential headache, causing larger than normal volume on the Champlain and Victoria Bridges.
The number of lanes available to regular commuters in the morning and afternoon rush hour will remain unchanged with the province turning the northbound side of the bridge into a one-way.
The AMT has also implemented emergency measures to convince drivers to abandon their cars on a clogged artery and take the train instead.
The AMT announced Wednesday afternoon that the number of departures from the Candiac commuter train terminus would be increased from six to nine, with the extra trains leaving the station at 6:35 a.m., 8:25 a.m., and 10:30 a.m.
In the afternoon, the three extra trains will depart from the Lucien L'Allier station downtown at 9:35 a.m., 3:55 p.m. and 5:55 p.m.
Some of those trains will include double-decker cars to carry as many passengers as possible.
Also, the capacity of the parking lots at the Candiac, St-Constant and Ste-Catherine stations, as well as the free parking at the Chateauguay station will be significantly increased.
"After getting the call we put our contingency plan into place," said AMT president Joel Gauthier. "I will be very happy to announce... that we will have extra commuter trains as of tomorrow (Thursday) morning."
Damage will take months to repair
Extensive construction work has been undertaken on the Mercier Bridge for the past several years, in what has been billed as the largest bridge reconstruction project ever in Canada.
Those repairs are expected to extend the life of the Mercier by 75 years, but they have turned up a host of hidden weaknesses in the bridge structure.
It is one of those weaknesses which is to blame for the sudden closure.
The structure of the bridge is composed of beams in an interlocking 'X' pattern, and a recent inspection determined that the gusset plates which hold the lower portion of each truss together were badly eroded.
Even though heavy trucks had been banned from the Mercier Bridge in December, 2010 because of fears the guard rails could not stop them in case of a crash, the newly-revealed damage prompted the bridge authority to recalculate how much weight the bridge can hold.
The new calculations convinced them to shut the southbound span of the bridge, originally constructed in 1934.
The engineers responsible for overseeing the repairs have not yet decided how to fix the damaged portions.
"Either we replace or we reinforce it," said Daniel Bouchard of the Bridge Corporation. "If we reinforce the gusset plate it's a permanent repair."
About 10 of these linking portions are affected, and each is a custom piece.
The northbound span, which was built 30 years later, does not have the same damage.