John,
Thanks again for your responses. Your comments on cycling integration are very informative. I appreciate your enthusiasm.
You mention Point Hope Shipyards as an example of a business being affected should the Johnson Street Bridge fail. I believe there are a number of questions to be addressed for this to be a valid point. Is the proposed bridge guaranteed to fully function after a large magnitude earthquake? Does the city have a contract with Point Hope Shipyards guaranteeing an earthquake-proof bridge? I could see the shipyards having a case against the city if the current bridge failed to rise again due to lack of mechanical maintenance but it’s not clear an earthquake would result in the same liability.
You examples of the Canada Line construction project in Vancouver and the I-35 bridge disaster are not particularly relevant as neither had anything to do with earthquakes.
In your response to my Times Colonist letter you bring up work being done on City Hall and Crystal Pool. I am glad the city is making progress on seismic preparedness for its other structures. You also note that the city has no inability to pay for a new bridge. The main point I take from the Law of Canadian Municipal Corporations quote by the Waterfront Trail work is the phrase “requirements of the public”. My interpretation is that, should Victoria hold a referendum with the results being no seismic upgrade, the economic liability the bridge represents may decrease substantially. I haven’t come across a reason to doubt this. I would recommend Council analyze this question before deciding to replace the bridge regardless of referendum results.
Finally I would like to point out it is still not clear what the seismic liabilities of the bridge actually are so there is no way to know if it makes economic sense to do the upgrade. A proper analysis by economical, legal and geological experts would go a long way here. If we consider a seismic upgrade a form of insurance on seismic liability we can use the basic equation (Not representing profit or administration costs):
Cost of insurance [cost of new bridge] = chance of event [earthquake] X cost of event [seismic liability]
If the “true” seismic liability is above the one calculated here an upgrade would be justified. If we look at a year by year basis and consider the cost of insurance $260,000 (yearly payment on $42 million) and the chance of a large earthquake is 2.5% we get a seismic liability of $10 million. If we look at the full cost over 50 years ($62 million after interest) with an earthquake chance of 6% we get a seismic liability of over $1 billion. This is obviously too simple to base any decision on but it is the sort of analysis that would convince me a seismic upgrade is needed.