About a million years ago, ROTC cadets at my Iowa high school heard our program’s active-duty sergeant shout out this nugget so often I can still hear his voice:
The message was absolutely clear. Try marching faster than your unit’s capability and you’ll end up with disorder and chaos. With that as background, here’s an exchange during last Thursday’s “Insights on PBS Hawaii” TV panel discussion show on the Honolulu rail project.
We started our review of the program a few days ago and now pick up the program during a discussion on whether the partially at-grade system proposed by the local chapter of the American Institute of Architects would have the same carrying capacity as the City’s proposed all-elevated 20-mile system between East Kapolei and Ala Moana Center. Host Dan Boylan directed a viewer’s question to Peter Vincent of the AIA's Rail Task Force:
Boylan: “Peter, someone wants to know: Does the light rail proposal change the per-hour capacity?”
Vincent: “It works in 34 other U.S. cities.”
Caldwell: “But it doesn’t go as fast. We’re paying for a system that’s fast and efficient. We’re trying to get (people) out of their cars who live in the ewa plain to come into town. If you don’t make it fast, if you don’t make it reliable and if you don’t make it efficient, they’re not going to get on it. They’re going to drive into town.”
Unlike architects, transit experts will tell you headways between trains driven by humans must be considerably greater than automated trains. Three minutes between trains with humans at the controls seems highly unrealistic, and Vincent’s suggestion that headways could be only 2 minutes for at-grade trains seems fanciful at best.
Another point Vincent made needs amplification – that at-grade trains could consist of three cars, each 90 feet long. Two hundred seventy feet (3 x 90) happens to be the approximate length of the shortest block in Chinatown, and an at-grade train can’t be longer than the shortest block to avoid blocking cross streets.
But the City’s elevated system can be longer than the shortest city block because trains would be completely unaffected by cross streets, so it’s obvious an elevated system with trains that each have greater capacity and operate with at shorter headways is much more efficient in moving large numbers of people than at-grade could ever be.
As Managing Director Caldwell said during the show, “…if you’re on the ground, you can go no faster than the slowest car….” That's pretty much what Sergeant Phillip Spinabella was trying to get across to his ROTC cadets decades ago.