Drivers might have to wait another two years before they can once again move along Margaret Avenue north of Victoria Street.

The Margaret Avenue bridge has been closed since late June due to structural concerns, and City of Kitchener staff have issued a recommendation, made public Wednesday, that the bridge remain closed until it can be replaced.

Engineers’ reports say the bridge could collapse without warning from three different causes, including the pullout of reinforcing bars, concrete failure and failure of welds in the support structure.

City staff say tearing down the existing bridge would be the safest and least risky option, as well as the best use of taxpayer dollars.

Alternatives would be explored to allow pedestrians to cross through the area.

The other option, bolting steel plates to the top and bottom of the bridge and building a replacement in 2015, would allow at least one lane of traffic to use the bridge in late 2013 and all of 2014, but would still present a risk of potential bridge failure.

“These steel plates do not take away the current deficiencies of the bridge, but they mitigate the risk of failure,” says Barbara Robinson, the city’s director of engineering.

Complicating matters is a natural gas pipe, 10 centimetres wide, carried by the bridge.

The pipe is the main natural gas supply for the Bridgeport area, and has been shut off since the bridge was closed, but alternative arrangements are necessary to prevent natural gas shortages in the area over the winter.

The Margaret Avenue bridge is the only bridge of its kind in Kitchener. A similarly designed bridge in Laval, Que., collapsed in 2006, killing five people.

The bridge design no longer meets Canadian bridge design codes.

Replacement of the bridge, which is currently being inspected three times per week, is estimated to cost a total of $6 million.

Installing the temporary steel plates would cost $400,000, plus the cost to replace the bridge in 2015.

“I think we all would be more comfortable if we knew we didn’t have to worry about this bridge failing,” says Robinson.

Councillors will make a decision on the future of the bridge next week.