Posted Apr 23, 2014, 8:40 PM
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Join Date: Mar 2008
Location: Nepean
Posts: 2,627
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I’m not sure that the problem was a lack of thought put into the process of converting the Transitway to LRT; rather I think that it was believed that there would be no need to convert from one technology to the other.
The decision to use buses for the main infrastructure was a deliberate one. The capital cost for buses was cheaper per rider (i.e., three buses cost less than one LRV), the runway for buses was cheaper (i.e., asphalt roadway is cheaper than tracks and over-head wires), buses are more flexible in their routing than trains (i.e., buses can run on roads, in mixed traffic, while trains must run on fixed tracks), and buses can be run on a fragmented system while an LRT needs a complete route (i.e., a Transitway could be built over time but a rail-based system would need all of the money up front). At the time of the decision, it was also believed that a bus system could carry almost as many passengers along a corridor as an LRT system could; so a later switch to LRT would be fruitless.
Based on what was presented, I am certainly not surprised that the RMOC went with buses for its rapid transit system; it was a decision that made the most sense - as I say, based on the information presented to them. A bus-based system would allow buses to pick up passengers in the suburbs and then enter the Transitway for an unimpeded ‘express’ trip to downtown, without any transfers. The Transitway could be built over time, with buses running along existing roads around any gaps, until the entire route was complete. There would be a base of ‘Transitway’ buses which frequently ran the length of the Transitway, much like a ‘metro’ line, to move large numbers of passengers who would transfer on-to and off-of the line. It sounded like the ideal system – at a bargain price. There really would not be any good reason to change from such a utopian system to LRT.
But the decision between BRT and LRT was not a smooth one; there was a strong lobby on either side of the debate. In order to ease the tension, it was easy for those who chose BRT to say that the line would be built to the same geometric specifications as an LRT system would require; that way, if needed in the future, a conversion could be done. But there was really no thought, in my opinion, that the line would ever actually be converted; it was a convenient thing to say to defuse a debate. It was true that the geometry of the line would be the same as needed for LRT, but that was simply coincidence; a vehicle, be it bus or LRV, will need a certain radius of corner for a given speed. [Later Transitway construction did use corners that were too tight for LRT, but they were also a detriment to bus speed. Those decisions were more based in politics than physics.]
The BRT system worked pretty much as planned – where it was completed. Unfortunately, the ‘flexibility’ of buses allowed the central tunnel to be postponed in favour of less expensive alternatives and buses were run through the downtown in dedicated lanes on the streets. This interaction with the transportation grid and other traffic led to interference with the buses, slowing them down and reducing bus through-put.
Another problem that emerged because of the ability to run ‘Express’ buses from the core to specific suburbs was that the number of different routes using the downtown bus-lanes was large; meaning that the bus platforms were crowded with people who were waiting for their specific bus. Having too many people on the platforms creates ‘turbulence’ loading and unloading passengers, which increases the dwell time at the stops and, again, reduces bus through-put.
It also turns out that labour costs to run nearly 900 buses became an unsustainable burden. Although the capital costs of a BRT system were supposed to be lower than for a train, the operating costs of moving passengers in the smaller vehicles proved to be a major problem. The benefits of buses came at a price that became too high.
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