More rail or more road? Bridges point the way
Consider the following table, then decide whether it makes
sense to build 38 more lanes of road capacity over the Fraser
river at a cost of $14 billion (as has been suggested will be
required to keep up with growth in automobile use).
| Bridge |
Cost |
capacity1 |
capacity2 |
| Cambie (over False creek) |
$53 million |
7700 |
16200 |
| Alex Fraser |
$106 million* |
7700 |
16200 |
| SkyTrain |
$33 million |
10400 |
21600 |
All capacities are given in persons per hour per direction.
Assumptions (car): one car every two seconds in each lane,
capacity1 assumes 1.43 persons/car (actual figure from GVRD
survey), capacity2 assumes 3 persons/car (assuming massive
carpooling)
Assumptions (SkyTrain): ultimate capacity based on 75 second
headways (although I have heard it claimed that 50 second
headways are possible), 6 car SkyTrains, 36 seats per car, 39
standees per car. capacity1 is seated capacity, capacity2 is
seated+standing capacity.
* According to a Ministry of Transportation and Highways
annual report, the total cost of the Fraser river crossing and
connector was $350,738,906. However another MoTH report,
"Brief to Commissioner Inquiry, Coquihalla and Related
Highway Projects, Sep 1987", gives the total cost of the
Annacis crossing as being $483 million. By adding up the value of
contracts pertaining to the bridge and its approaches I obtained
the figure $106,186,760 as being the cost of the bridge. The main
span alone cost $59,035,382.
James Strickland
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