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Cake day: June 30th, 2023

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  • Porque no los dos?

    Rabbit hole incoming: If you have to pick one, I suppose it depends on what metric you are trying to maximize. One doublestacked intermodal train car takes two long haul trucks off the road. One Siemens Venture passenger train car takes 74 people, or about 50 cars at 1.5 people per car, off the road. You can generally run longer freight trains than passenger trains, but 25x to normalize for VMT (which could be used as an approximate measure of direct health impacts from driving: crash risk, elevated blood pressure, obesity. It could also be used to approximate societal impacts of car culture: real estate dedicated to surface parking, voting bloc size that supports car-centric planning and development regulations) is probably excessive. On the other hand, if we normalize for emissions (hard to find data here, but as far as I can tell trucks are on the order of 10x as emissive), that gets us down to 5x train length, which is about on par (northeast corridor trains are typically in the 1/6 of a mile range, and median freight train length is somewhere in the 1-1.5 mile range from what I could find), and if we use infrastructure damage/maintenance cost (trucks are about two orders of magnitude worse than even today’s SUV saturated passenger car market, I’m assuming without reason or evidence that damage to steel rail infrastructure between a freight and a passenger car scales significantly less harshly for the sake of simplicity), things look downright strongly in favor of freight traffic. At the end of the day, it probably just depends on which use case has more unmet demand on a case by case basis. Of course, both pale when compared to the opportunity that high speed rail gives to take short haul flights out of the sky, but that is another set of analysis and does partially correlate to the elevated infrastructure cost of high speed rail vs conventional rail.



  • This makes one of the “solutions” from the article: “A law was introduced at the end of 2023 that will eliminate the need for permits and environmental impact assessments for bridges that are being widened to add lanes as part of renovations.” look particularly shortsighted. Infrastructure is a maintenance debt that we are reckoning with, so we will make it easier to build specifically bigger infrastructure so that in 25 years we will have an even bigger problem to solve? Not to mention the concept of induced demand meaning that those lanes are going to increase the amount of vehicles using the bridge, which would be exactly the kind of thing that should get an environmental assessment, versus repurposing some lanes for sustainable transit or building a separate bridge for those modes


  • If you are going to and from points within a solar system, probably but not necessarily. Every transfer made between gravitational influences increases the chance that you will enter at an angle to the equatorial plane, especially if the two influences are not coplanar traveling between solar systems would likely have you entering at a significant angle. Furthermore, approaching a ship at a low velocity means slowing down as you approach them, so even if you do approach coplanar, it would be engines first and not nose first (unless star trek vessels have an ability to reverse their propulsors? I don’t know if that’s ever been shown aside from by approaching things nose first). The expanse showed this aspect of space interaction well with the flip and burn maneuvers