Montreal Overpass collapse

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Highway overpass collapses near Montreal

On September 30, 2006, part of an overpass (65 foot section of a three-lane overpass (The Associated Press 2006a) collapsed in Montreal (Laval) on Concorde boulevard running over Autoroute 19. The collapse crushed two vehicles under it, killing five people and seriously injuring six others who went over the edge while travelling over the overpass (Marotte & Magder 2006). This closed Autoroute 19 for almost 4 weeks (CanWest News Service 2006), "disabling an important north-south link between Montreal and its northern suburbs as well as the Laurentian region" (The Associated Press 2006a).

1 Immediately Before
- 1.1 What people Noticed
- 1.2 Responses to calls
2 Bridge History and Design Problems
3 Suspected Cause
4 The Aftermath
- 4.1 Behavioural effects
- 4.2 Agency responses
  - 4.2.1 Detour Routes
  - 4.2.2 Donations from other Provinces
5 Learnings
6 See also
7 References
8 External Links

[edit] Immediately Before

[edit] What people Noticed

A number of people had noticed that the overpass wasn't in good repair:

"People living near de la Concorde and Highway 19 told The Gazette they had noticed the overpass had begun to crumble in recent months" (Lunau, Coates & Banerjee Branswell)
Carole Hackenbeck, less than a month before the collapse, noticed that there were "unusually large gaps and misaligned spacing in the deck-support structure underneath" (The Associated Press 2006a).
"One witness told TVA television network that he noticed the road had sunk an inch or two when he travelled over the overpass minutes before the collapse, and he called emergency dispatchers" (The Associated Press 2006a).
Also, "several motorists told LCN they had called police up to an hour before the collapse to report seeing fissures appearing in the overpass roadbed and chunks of concrete falling to the road below" (Reuters 2006a).

[edit] Responses to calls

When the Quebec Ministry of Transport was contacted regarding blocks of concrete falling onto Autoroute 19 from the Concorde Boulevarde overpass above, a patroller was sent to do a sight and sound test (Lunau 2006) to gauge whether the road should be closed and to clear away to concrete hazards; this was 30 minutes before the collapse (Marotte & Magder 2006). Neither roads were closed (Lunau 2006) as the official concluded that the bridge presented no immediate danger (Marotte & Magder 2006). The patroller however did demand that an inspection be carried out as soon as possible, but was told "that an inspector would show up only on Monday, two days later" (Charron 2006).

The Ministry also sent out messages to journalists and traffic reporters warning of the concrete debris; this was confirmed by Josee Seguin, a spokeswoman for the Ministry (The Associated Press 2006b) (Lunau 2006).

[edit] Bridge History and Design Problems

The overpass on the Boulevard de la Concorde (Concorde Boulevard) was built in 1970 and was expected to have a life of 70 years, of which it only lasted 36 (Arseniuk 2006). David Lau, as apart of an article for the Ottawa Citizen, suggests that this estimation of 70 years was inaccurate. They underestimated traffic volumes; they also did not take into account that "the amount and weight of trucks [on] today's roadways are significantly higher" (Arseniuk 2006). "30 or 40 years ago, engineers could not anticipate the traffic some of their bridges would be forced to accommodate in the coming decades" (Arseniuk 2006). Michel Despres (Transport Minister of Quebec) stated that it is inspected once a year, and gets a more in-depth inspection once every three years (Lanau 2006), last being May 2005 (Marotte & Magder 2006). Ken Bontius, a civil/structural engineer at Hatch Mott MacDonald adds that the bridge is examined bi-annually by structural engineers (Arseniuk 2006).

[edit] Suspected Cause

It has been suggested that the weather conditions are partly to blame for the overpass collapse. A common practice during the winter months is to salt the roads to melt the ice that forms during harsh winters. "A. Ghani Razaqpur an engineering professor at McMaster University in Hamilton, president of Canadian Society for Civil Engineering", as part of an article for the Canadian Press posited that the overpass "succumbed to... corrosion of the steel reinforcements bars inside the concrete" as well as wear and tear (Marotte & Magder 2006). Ken Bontius agrees that "Salt for traction... deteriorates a structure" (Arseniuk 2006).

[edit] The Aftermath

After the collapse of the overpass, the government moved quickly to rescue survivors, remove the dead and clear away the debris.

[edit] Behavioural effects

The Monday (October 2) following the collapse, as everyone was trying to get to work, three major expressways into Montreal from Laval were gridlocked with vehicle line-ups stretching for kilometres (Marotte & Magder 2006)(CTV News 2006). "Traffic was backed up as early as 6:00am on Quebec Autoroute 25 and Quebec Autoroute 15" (CBC News 2006a).

Normal traffic flows along Autoroute 19 amount to 57,000 vehicles per day in both directions (CBC News 2006a). The collapse caused some changes to these figures with motorists choosing different routes (mainly official detour routes), changing the time they left for work (earlier or later) or change in mode (to bus, subway, etc.) being the main responses.

[edit] Agency responses

In response to the incident, the Quebec government instigated several strategies to speed the recovery effort and to minimise the inconvenience of commuters. The Quebec government made it a priority to rescue survivors, remove the dead and the debris from Autoroute 19. The demolition work (of the Concorde Boulevard) closed Autoroute 19 for a little under four weeks (CanWest News Service 2006) and caused "motorists [to] get up earlier and use special buses to commute into the city" (Canadian Press 2006). These buses were shuttles provided to ferry commuters between new park and ride sites and subway stations.

The government also put detour routes in place, urged commuters to take public transport and to carpool (CBC News 2006a) (CTV News 2006). CAA-Quebec, a non-profit organisation also has urged commuters to consider carpooling as an alternative to driving, suggesting their free carpool ride-sharing program which allows drivers and passengers to network to organise carpools (Canada NewsWire 2006). Transit authorities in Laval and Montreal also increased services on some routes to accommodate more commuters (CBC News 2006a) (Marotte & Magder 2006) (CTV News 2006):

An extra commuter train
Extra park-and-ride parking lots including a free bus shuttle to subway stations - to encourage commuters to not use the already overtaxed detour routes
Reserved bus lanes extended
Adding 6km to two high-frequency bus routes (Riga 2006)
More buses

Riga (2006) interviewed Marc LaForge from the Societe de transport de Laval about the transport department suing Transport Quebec to pay for all these extra services:

"Laval's transit authority - the Societe de transport de Laval - is asking for $312,500, for now. That's $12,000 for each of the 25 weekdays from October 2nd to November 3rd on which it provided extra services for commuters whose routes were affected by the collapse" (Riga 2006).

Costs also included paying overtime to drivers (Riga 2006).

[edit] Detour Routes

The official detour routes were as follows:

Autoroute 25

Autoroute 15

Autoroute 40

Autoroute 440

Route 335

Route 148

The Quebec Transport Department produced a diagram of the detour routes - Autoroute 19 Detour Map.

[edit] Donations from other Provinces

To aid Laval commuters, and to help the province cope with traffic problems (Artuso 2006), Ontario donated a "GO train" to increase ridership in the wake of the weekend collapse. Ontario's premier Dalton McGuinty - "[Quebec officials] tell me there has been an increase, [a] fairly dramatic increase, in demand for the rail." Also "There's a rail line that runs along the site of the tragedy, and more and more people want to use that rail line" (CBC News 2006b).

[edit] Learnings

Because of this event and another that occurred in 2000, it has highligted to the Quebec government that their road infrastructure is in disrepute and that if they keep putting off repairs and upgrades, there could potentially be another fatal accident. "The Quebec government is spending $200 million on highways this year [2006] and is to boost the amount to $220 million in 2007" (Lunau et al. 2006).

This will be good news to the Canadian Council of Professional Engineers (CCPE) as they have been campaigning for infrastructure renewal and maintenance. "Hopefully this tragic event did not happen in vain and we, as a society, will learn from it and make the conscious decision to re-invest in infrastructure using a long-term, holistic approach as well as life-cycle management guidelines" (Evans 2006), Marie Lemay the CEO of CCPE says. "long-term adequate financial resources are needed from all levels of government in order to support a sustainable and planned approach over the full life cycle of any infrastructure project" (Evans 2006).