Double Decking

A guest post from regular commenter Garlynn Woodsong:

Recently, we have discussed the testing in San Francisco of a double-decker bus, which will then move on to Las Vegas, NV to go into full service as a part of the fleet serving their Deuce line. Tri-Met is currently running its fleet on B5 biodiesel, and plans to ramp up the percentage of biodiesel in the mix as more supplies become available from local production. Tri-Met is also currently testing/running some hybrid-electric buses on some of its lines.

What I’d like to cover in this post is the possibility of introducing hybrid, double-decked buses to Tri-Met’s fleet. Apparently, London has already ordered them, and they will enter revenue service there in a couple of years.

Not only would they provide additional capacity per driver, they would have lower emissions — hybrid buses generally tend to post about 30% lower emissions (or 30% better fuel economy, if you prefer), resulting in a 15% decrease in operating cost. Combining this with the lower operating cost per rider of a double-decker bus, and some real money-saving could be possible! Running such a bus on biodiesel would further reduce its emissions.

There could also be more room for bikes, using hooks inside the bus. Some new low-floor, double-decker buses (such as this one) have as many as 78 seats on the two-door model, with 31 downstairs and 47 upstairs. It might be possible to not only put a 2-bike rack on the front of such a bus, but also include MAX-style vertical bicycle hooks on the inside of the vehicle for a few more bicycles by removing seats/taking multiple advantage of the wheelchair area (making it into a more flex-space zone to accommodate either wheelchairs, bicycles, luggage or standees, depending on conditions — with of course wheelchairs always having the option to pre-empt any other use).

Clearance, however, would be an issue. Not every route would be eligible for a double-decker bus. A hybrid double-decker bus is likely to be between 13.5 and 14.5 feet in height. With a vertical clearance of only 13 feet, the Broadway Bridge would thus be off-limits to such buses. With a vertical clearance of 15.7 feet, however, the Hawthorne Bridge would be fair game!!

Introducing such buses on the 14-Hawthorne might therefore be feasible — though, of course, we would only want to see this as an interim step on the way to a streetcar line on that particular route — right Bob R? Similarly, double-decker buses would likely be feasible for routes such as the 20 and the 12 that cross the Burnside and other bridges with no vertical clearance issues. Some vertical clearance issues might present themselves due to low overhanging trees on some routes, especially near bus stops that don’t have curb extensions, but these would need to be evaluated on a route-by-route basis.

Certainly, Vancouver, B.C. is another West Coast city that is running double-decker buses successfully, as a way to cost-efficiently add capacity on their trunkline routes running radially out from their downtown.

Some drivers from Hong Kong have reported hauling crush loads of over 200 people on double-decker buses in service in that city. I remember riding the 19-Woodstock, years ago when it was served by the 200-series buses, and the driver declared that our run regularly had over 100 people at the height of its crush load. This suggests that it is possible to almost double the capacity of the bus by adding a second level and going double-decker — which is amazing, when you account for the space lost by the stairwell! (Granted, folks in Hong Kong are likely to be slightly smaller than folks in Portland, so we might never see 200 people actually fitting into a crush load on a bus here, unless it was on a bus serving an after-school run…)

As Tri-Met searches for ways to squeeze more capacity out of its limited operational budget, I suggest that running double-decker buses might be a way to achieve the goal of more passengers per driver. Articulated buses are not likely to make a re-appearance in Portland, and not every bus route that has capacity issues can be converted to a streetcar line. For those lines that don’t have vertical clearance issues, going double-decker would seem to be a worthwhile proposition. And as the technology becomes more widely available to do so, it would make sense for these double-decker buses, like all new buses that Tri-Met orders, to also be hybrid-electric (like the 800 new series-hybrid buses that New York City has ordered, featured in this article).


Wright Eclipse Gemini Double-decker bus

Wright Bus most similar to an Electrocity, the hybrid-electric double-decker bus currently being tested in London

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