You have to build rail to get this kind of new capacity. That 14,000 people per hour is eight northbound lanes (four general, four express) of traffic. Link will move more than half again that many. What would it cost to put four or five more lanes each way on I-5 in Seattle? Where would those cars go once they got into the city?

And remember, all these new light rail trips have no congestion. Those I-5 trips are often at a dead stop – but those light rail trips are cruising along between stations at 55mph.

8 Replies to “Sound Transit 2’s vast capacity increase”

  1. ok, now we have a source for your earlier data.

    1) Now, do we know what percent of the light rail riders (let’s use the I-5 corridor) in 2030 are being pulled from buses vs. autos? In other words, what percentage of that light rail ridership consists of people who left driving for rail?

    2) Do we have projected average travel times across all modes of transportation – auto, bus and rail – for this (say Lynnwood to Seattle) segment in 2030?

    Question (2) is aimed at finding out how higher “throughput” in 2030 translates into travel time reduction for all riders (auto and transit). It is very difficult to find an answer to this question, incidentally (and from a strictly mathematical perspective, higher throughput does not translate into reduced delays, so there is nothing obvious about the higher throughput data).

    Just so you’re aware, I support light rail generally, but like a lot of people I want to understand what we’re getting for our money in Prop 1.

  2. Neither of these questions have simple answers, but neither also are relevant to a cost-benefit analysis of Prop 1. It depends on when in the day you’re taking your average travel times – again, the targeted areas are peak commute direction and volume, because those are what limit our economy. Averaging those with 2am trips is pointless, because those trips don’t need capacity additions.

    The data you have now is targeted toward answering the pertinent questions. Perhaps I should write a post about why blanket questions aren’t really relevant, because the vast majority of the jobs that produce the most value are 9-5?

  3. The sources for all my data are all there, you just don’t seem to be motivated enough in your curiosity to do a little looking.

    (1) is partly irrelevant because most of the riders are new trips, not “pulled”. They’re people who are kids now, who aren’t set in their ways and will make decisions based on what’s available to them at the time they start setting their habits.

    It’s also partly irrelevant because light rail ridership is double or triple the existing bus ridership in the same corridor, *total*. If you just assumed that every bus rider switched to rail where it was possible for their trip to be accomodated, you’re still looking at a relatively small part of the rail riders, and the benefit of rail to the pure car users would still be 3 or 4 new lane equivalents.

    If you want to understand that split, go read some of the voluminous reports on other new light rail systems. I’d say start with Denver, because I know a lot of research has been done. Use google!

    And take note – those bus riders would get to work faster. Congestion for them will decrease and reliability will increase for those switching to rail, just as it does for the car users.

    (2) you can do with the data you already have. Use the peak hour, and use the average trip times the P-I put on that graph. You see a reduction in travel time average. I can’t really believe you’re even serious about that math – if 38% of your users have HALF the travel time, and the increase from now to 2030 for cars is only about 10%, it’s pretty obvious your average is going to be lower.

  4. Neither of these questions have simple answers, but neither also are relevant to a cost-benefit analysis of Prop 1. It depends on when in the day you’re taking your average travel times – again, the targeted areas are peak commute direction and volume, because those are what limit our economy. Averaging those with 2am trips is pointless, because those trips don’t need capacity additions.
    ***************

    Then let’s frame it from a very practical perspective that people can relate to. The year is 2030, and light rail runs to Lynnwood (and I hope it does).

    1) During this commute what is the projected average travel time from Lynnwood to Seattle for all transportation modes?

    2) How does the number from (1) compare to the number today?

    Regarding this, “but neither also are relevant to a cost-benefit analysis of Prop 1,” the previous questions are highly relevant if you pay taxes and want to know how money is going to improve local driving conditions. Specifically – and this goes back to a previous question – I would like to know what percentage of light rail riders in 2030 will leave their autos for rail vs. left riding the bus. If only a small percentage of those rail riders had been willing to leave their autos, that’s a big issue because it means we haven’t done anything to reduce congestion, but only provided an alternative for bus riders and a small percentage of auto drivers. People want to understand that in the analysis.

    Again, this is not an argument for roads, far from it.

  5. Seriously, you have all the data you need (and if you don’t, you can do a little digging on WSDOT’s site for I-5 capacity). I don’t see why you keep asking this question? Are you just trying to get me to do the work for you?

  6. By the way, it again looks like you failed to read my comment. You’re just repeating the same things over and over without paying attention to what I’m adding.

  7. Seriously, you have all the data you need (and if you don’t, you can do a little digging on WSDOT’s site for I-5 capacity). I don’t see why you keep asking this question? Are you just trying to get me to do the work for you?
    **************

    If you’re going to get voters to part with their money and pay the huge sums Prop 1 requires, you’ll have to tell a convincing story that addresses these types of questions. The onus is not on voters to dig these details out – few have the time and the data is all over the place. In a public forum of ordinary citizens you would have to be prepared for detailed questions like this.

    If there were time I would consider organizing a community forum for just this and invite you. It would be a good experience.

    I can see you have passion for light rail, and I admire this.

    Back later.

  8. 99% of voters don’t do cost-benefit analyses. They know that we need more capacity, and they know it’s cheaper to build that capacity with mass transit – not because they’ve done the numbers, but because they see full mass transit in every other city where it’s built.

Comments are closed.