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Originally Posted by Dado
You're starting to sound like Andy Haydon.
A bus tunnel would have to be wide enough for two lanes. That's a lot more material to pull out. We may even need two of them (if the 1988 study is followed, which it likely would be). The stations would probably be built with two lanes per direction, though it'll prove pointless. The stations themselves will have to be side-loaded, so no cost savings there. The way DOTT has increased, I doubt the bus tunnel(s) would come in at less than $1B.
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If the bus tunnel is only meant to be a medium-term fix (i.e., it will be eventually converted to rail), then one three-lane tunnel would probably be sufficient. If, on the other hand, it were meant to be a long-term fix, I would strongly recommend that two two-lane tunnels be built in order to maximize capacity. That, combined with careful station design and measures to reduce dwell times, would allow the tunnel to accommodate at least 300 articulated buses per hour per direction (i.e., serve both Ottawa and Gatineau demand).
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The worst of it all though is that it won't solve congestion nearly as much as people think it will. People keep thinking that it's the cross streets that cause the delays, but they're not the biggest source of problems. It's simple dwell time. It always has been. Tunney's Pasture Station already suffers from minor westbound jams in the evenings, and it has a lot less loading than will the downtown stations, which, if the logic of the DOTT applies, will only be two in number and therefore really busy.
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I agree that dwell times is the main problem (although poor station design ranks as a close second). What has OC Transpo done to reduce dwell times? Well, surprisingly little. Can more be done? Absolutely. It is well-known that to substantially reduce dwell times, you need the following:
One, fare payment prior to boarding. I think most people acknowledge that this would make a big difference. I remember that, a few weeks ago, you posted in another forum an article on the bus tunnel that was written 20 years ago. Here’s a quote from the article that caught my eye:
"The other report, tabled Wednesday, recommended ways to extend the life of the current bus lanes on Albert and Slater Streets. It says construction of a tunnel can be delayed as long as 16 years by timing traffic signals to favor the bus lanes, installing passenger information screens at bus stops and allowing passengers to prepay cash or ticket fares at the bus stops." I’ll be generous and assume that they implemented the timing of the traffic signals. However, 20-years later, they still have not implemented fare payment prior to boarding, nor have they installed passenger information screens at bus stops, even though they acknowledged that it would produce a large increase in capacity.
Two, no interaction between drivers and users. I cannot stress how critical this is. The last time I had to board a bus at Hurdman every bus (#85, #106, etc.) that stopped at platform 1C was besieged by people wanting to know why their feeder bus was late and where it was. A whole platform was shut down for a period of ten minutes during the tail end of the PM peak because of this. This inevitably resulted in a serious bus jam affecting all of the platforms and delays for hundreds, if not thousands, of riders.
Three, all-door boarding. Ideally, you should have four large doors on every articulated bus (two in the front and two in the back). However, Ottawa could get by with the current three-door models until they needed to be replaced.
Four, leveled boarding. This would be the hardest to implement since you would probably need a fleet of new buses with ramps on every door that could be deployed quickly (à la Curitiba). Short and medium term, you could get away without it, but eventually you would need it.
Five, simplify routes. OC Transpo and STO would need to simplify their network and use a modified version of hub-and-spoke. In the central area (i.e., between Bayview and Hurdman), there would probably be five or so regular routes and five or so trunk express routes.
All of these measures (except for trunk express routes) have been adopted by rail rapid transit systems and that’s because they dramatically reduce dwell times. If you do the above, you’ll get bus dwell times below 15 seconds, even at the busiest stops during peak periods.
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The interesting thing about the failures at Tunney's is how useless the passing lane actually becomes. Once the platform is full of buses, drivers arriving have little choice but to join the queue since they can't tell if there are passengers to pick up or not without going past the platform (since westbound express routes pick up passengers at Tunney's, virtually all buses have to go past the platform). If the platform isn't full, they can sometimes overtake some of the buses that are there and stop, but once the platform fills up that option disappears. Drivers arriving later won't overtake those who are already waiting while those already in the queue can't necessarily see when a spot opens up. Luckily the jams usually clear at Tunney's because even though all express drivers go past to see if anyone wants to get on, not every one actually ends up needing to stop. But downtown - that will not be the case. Every bus will stop every time and the passing lanes will only be of marginal benefit. In a way, even John Bonsall realized this in November 2007 when he suggested in his promotion of bus tunnels that two lanes were not necessary at stations in the tunnels (though he forgot about the need to be able to pass disabled buses in the narrow bore tunnels).
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The Tunney’s Pasture situation that you describe flows from OC Transpo’s failure to implement measures that would minimize dwell times (see above) and poor station design. In the case of the latter, there is insufficient space between 1A and 1B (westbound platforms) and thus, during the peak, a bus wanting to stop at 1B has difficulty overtaking buses that are stopped at 1A. Best practices guides suggest that the spacing between platforms should be at least 30 metres. Tunney’s Pasture is nowhere near that. With smart station design, the passing lanes become very useful and also allow trunk expresses to bypass most stations.
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The tunnels approaching either side of the Downtown East station would be clogged up with buses because the passenger loadings of ~2.5 current stations (Metcalfe, Bank and some of Kent) would be going through the East station. The congestion problem would just be moved underground, out of sight and out of mind.
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The busier stations, such as Downtown East and Rideau Centre, would need to have three platforms in each direction and be close to 200 metres in length. Platform 1 (to be used by regular OC Transpo routes) and Platform 2 (to be used by trunk express routes) would each have two stopping bays, while Platform 3 (to be used by regular STO routes) would only have one stopping bay. There would be sufficient distance between the platforms (i.e., 30 metres) to provide for queuing space and allow buses to easily overtake each other. With such a set-up, the station could serve five articulated buses at the same time and maintain low dwell times. Dedicating routes to specific platforms would lower the number of routes per platform (to five or less) and thus help reduce the amount of jockeying that occurs (all-door boarding and fare pre-payment would also help in this regard).
Less busy stations would be much smaller (with perhaps only one platform since they would be bypassed by trunk expresses).
Personally, I would bite the bullet and add an extra station (Downtown Central). By doing that, you could downsize Downtown West and have trunk express routes bypass it.
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And so the current high-cost model would persist.
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You must mean high operating costs. That is the only real downside that I can find with a properly-designed bus tunnel.
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