Is a new high-capacity transit system worth the visual encumberments it will cause? Should the views of a beautiful tropical city be obstructed for the benefit of passengers on public transportation? That’s the question now being debated in Honolulu, which is planning an elevated rail line that will run throughout the city.
Hawaii’s biggest city is planning a 20-mile transit line, running from Kapolei in the west to Ala Moana Center downtown, via Waipahu and the airport. Honolulu’s density is high enough to require a rail system with a fully independent right-of-way; the city’s The Bus transit system already carries an average of 225,000 riders a day, and the new line is expected to transport a full 95,000 of those passengers by 2030. The first phase of the system is expected to be completed by 2018 at a cost of $5.8 billion, with construction possibly beginning late this year.
Yet, while the elevated alignment has been set in stone for more than a year now, the city’s chapter of the American Institute of Architects is now asking the city to run the system at ground level downtown so as not to obstruct views in that dense waterfront area. The architects argue that Honolulu’s landscape will be decimated by the concrete guideways. The elevated route would run on an aerial viaduct 30 feet off the ground (visualized in the before-and-after pictures above). An underground subway isn’t an economically realistic option.
The negative consequence of moving the trains to ground level would be significant: overall trip time would increase by 10 minutes and automated operation would be impossible. If current plans play out, on the other hand, Honolulu’s system would probably operate like Vancouver’s SkyTrain, which has driverless vehicles running on third rail electric current. More standard light rail lines require drivers and overhead catenary, both of which increase operating costs, but which allow for street-running trains.
There’s no doubt that the elevated guideways aren’t going to be pretty — nobody likes huge concrete bridges spanning neighborhoods, which may find themselves plunged into occasional daytime darkness depending on the position of the sun. In addition, stations will be more difficult to access because they’ll be elevated over the sidewalk.
But the advantages of overhead rails come in the form of speed, because a SkyTrain-like system never encounters traffic, whereas LRT lines are all too frequently delayed by vehicles getting in the way. Driverless systems also have higher and more stable acceleration rates. Transit’s travel time benefits over automobile commuting is debatable, reducing public transport’s attractiveness to potential riders. Any effort to increase the speed of transit offerings would likely increase the number of people switching modes.
It’s a wash, then.
Are there potential compromises? One option is opting for extensive viaduct treatments downtown that would make the elevated line look less imposing and sinister. If the city invested in exciting artwork and lighting treatments along the bottom of the guideway, an aerial track might be something of an attraction. Similarly, a ground-level line could function well if fully separated from automobile lanes and given traffic signal priority at every intersection, modifications that would eliminate at least some of that 10-minute gap between the two alignment options. On the other hand, that would require a significant drop in the level of service offered to car drivers in areas near the line, something that’s not the easiest thing for which to advocate.
No matter whether an elevated or ground line is picked, though, the city would do well to consider seriously about how to minimize its respective drawbacks. Without that thinking process, Honolulu won’t get as good of a transit corridor as it deserves.
Image above: from Honolulu Star-Bulletin