Quote:
Originally Posted by TakeFive
Which city is getting the best Return on Invested Capital?
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This is a good point. Certainly lower cost lines can be worthwhile, which is precisely why Denver choose EMU rather than subway for most of its lines (which was absolutely a good decision). But there are several holes in your thinking:
1. Comparing cost per mile to overall ridership isn't right. Either compare overall cost to overall ridership, or cost per mile to ridership per mile.
2. Cost comparisons across cities must factor in several different variables. For example, are costs so high in Seattle because labor and materials are more there, or because there's something about their line that's makes it cost more to build? Or both? If we're talking about what Denver could have achieved for its money, cost comparisons from other cities don't tell us a whole lot unless we much more carefully control the variables. Phoenix is a pretty good comparison because labor & material costs are roughly similar and the lines are 99% on the surface. Seattle isn't.
3. Another variable is the question of what we're trying to achieve with a new line. One mile of core downtown line that the entire system is built around is much more valuable than one mile of outlying park-and-ride track, no matter what the cost per mile is, because the entire system is dependent on that expensive central segment.
4. Future plans for TOD also matter. How much additional density are we going to get around the stations? If 4 stories on one side of a highway is all we'll allow, it's going to be pretty low.
Quote:
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Originally Posted by TakeFive
You have two options. One option is to build one 10-mile line where ridership will quickly be near ridership capacity - very impressive. OR, for the same money, you can build 3 lines with 35 total miles that aren't near capacity - bummer, but have plenty of room to grow ridership. Which option is better?
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This depends on many factors. You seem to be assuming the total future ridership potential of option B is higher than option A because it's longer and has more room to grow, but that's not necessarily the case. A park-and-ride line that relies on commuters has a much lower ceiling for ridership than an urban line. If you built 3 lines with 35 miles total, even after 30 or 50 or 100 years you might very well still have lower ridership than 1 ten mile line in a better location. Especially if your stations aren't good at accommodating TOD.
Beyond that, timing also matters to any cost-benefit analysis. Let's say every rider is worth $1 in benefit. Let's say, hypothetically, that your one 10-mile line has 50,000 riders per weekday and 25,000 riders per weekend day in year one, and that ridership stays flat forever (ie no growth).
260 weekdays per year * 50,000 = $13,000,000
105 weekend days per year * 25,000 = $2,625,000
Total = $15,625,000 in benefits each year
Option A over 30 years = $468,750,000 total benefit
Now let's say your 3 lines get 10,000 riders per weekday and 2,000 riders per weekend day for the first ten years, reach 25,000/5,000 for years 10-20, and 50,000/10,000 for years 20-30. Your end ridership is almost equal (lower on the weekends because of commuter-only focus). But your benefits calculation looks like this:
FIRST DECADE:
260 weekdays * 10,000 = $2,600,000
105 weekend days * 2,000 = $210,000
Total benefit/year first decade = $2,810,000
Total benefit first decade = $20,810,000
SECOND DECADE:
260 weekdays * 25,000 = $6,500,000
105 weekend days * 5,000 = $525,000
Total benefit/year second decade = $7,025,000
Total benefit second decade = $70,025,000
THIRD DECADE:
260 weekdays * 50,000 = $13,000,000
105 weekend days * 10,000 = $1,050,000
Total benefit/year third decade = $14,050,000
Total benefit third decade = $140,050,000
Option B over 30 years: $230,885,000 total benefit
It's less than half the total benefit, because you're accruing the full benefit the entire time for option A, but it takes decades to see real benefit for option B, and you never actually catch up to option A unless your total ridership for option B grows significantly larger over time, which there's no reason to think it will.
Of course this is totally hypothetical and in real life the numbers would be completely different for any number of reasons. The point is simply to illustrate how benefits now do indeed have higher value than benefits that take decades to become reality.
That doesn't mean we shouldn't plan or invest in the future. Of course we should. But it does mean that if there's a huge need today, ignoring it in favor of a potential future need costs us real money.
And of course, if your option B system is highway focused, and your TOD plans are consistently low-density, then your ridership ceiling on option B is going to be pretty low no matter how many miles you build.
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