Autonomous vehicles, planes and high speed rail

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Submitted by no_such_reality on April 10, 2016 - 7:58pm

Looking twenty-ish years down the road, will automous vehicles kill commuter trains, high speed rail and planes for regional travel?

California's high speed rail,plan is essential San Fran to San Diego with dozen other stops.

As automous vehicles take over will they replace regional flight?

If auto drive crs take the ride to San Fran, Phoenix back to 4 or 5 hours, will you bother hassling with an airport?

Is there any reason to take HSR?

Submitted by spdrun on April 10, 2016 - 8:44pm.

Depends how either is implemented. I had to go to a town in east-central PA last weekend. Took the train. Outside of cities (per my phone's GPS), the train was doing 110-120 mph, with not many stops. This wasn't a "high speed train" -- those were late 70s era rail cars being used between NYC and Pittsburgh.

No way a car (automated or not) being driven in a safe manner would beat that speed. Plus there's something to be said for shared facilities, bathroom and bar car. Hard to do either in motion unless you're in an RV.

Submitted by mike92104 on April 10, 2016 - 8:46pm.

I think there will always be a combination of all of them.

Submitted by spdrun on April 10, 2016 - 8:50pm.

Also, assuming CO2 is a concern, EVs are distance/charge-time limited, even more so in very hot or cold weather. Electric trains are basically unlimited-range EVs. Combining them with ZipCar type (autonomous) vehicles at the stations would yield an interesting transportation network.

And who says the trains themselves won't be more heavily automated? If they don't need a driver, it would be cheaper to run one or two car rail vehicles, 5x more frequently than we run five or ten car trains today.

Submitted by AN on April 10, 2016 - 11:39pm.

I personally think autonomous car will be the death nail in the public transit coffin. Once every car is autonomous, then you can picture a very efficient system, along the line of a system in the iRobot movie. If I need to be in SF the next day, I can leave SD the night before, go to sleep in the car and wake up at my destination. Why should I even bother with a train. Also keep in mind that the current speed limit is set because of human. If every car is autonomous, I'm sure it would be safe for every car to be traveling at >100MPH, since they all will know where other cars around them are and where they're going, so there would never be any surprise.

Submitted by livinincali on April 11, 2016 - 6:22am.

AN wrote:
If every car is autonomous, I'm sure it would be safe for every car to be traveling at >100MPH, since they all will know where other cars around them are and where they're going, so there would never be any surprise.

It might be safe but it wouldn't be efficient. Cars traveling at 100+ mph use up a a lot more fuel/energy than a car traveling at 55 to 65 mphs. Autonomous cars should be able to draft better though.

As for high speed rail. I like the idea of it but I don't know that the cost of California's project is worth it. Last I heard the project was going to be over $100 billion. That just doesn't seem to be worth it.

Submitted by spdrun on April 11, 2016 - 7:46am.

Autonomous cars will be unlikely to draft. The "cars following a foot from each other" thing is a myth. Any autonomous car would have to be as safe as possible for the manufacturer to avoid lawsuits. Even if you remove reaction time, braking distances vary significantly between vehicles, even vehicles of the same type (depending on load, tires, etc). Following distances might be slightly reduced, but not enough to draft.

Submitted by livinincali on April 11, 2016 - 8:56am.

spdrun wrote:
Autonomous cars will be unlikely to draft. The "cars following a foot from each other" thing is a myth. Any autonomous car would have to be as safe as possible for the manufacturer to avoid lawsuits. Even if you remove reaction time, braking distances vary significantly between vehicles, even vehicles of the same type (depending on load, tires, etc). Following distances might be slightly reduced, but not enough to draft.

They are already testing platooning/drafting autonomous trucks in Europe. Maybe not drafting to the degree that is optimally efficient but enough to get some fuel/power saving efficiency.

http://bgr.com/2016/04/07/self-driving-t...

Submitted by spdrun on April 11, 2016 - 9:14am.

I've been reading about tests of platooning literally since the 90s. Practically, it's a recipe for a pileup if there's a mechanical failure or unexpected event (something falls off a vehicle, etC).

It might work for unmanned trucks, where only the cargo is at risk. Cars with people in them won't follow that closely. If anything, there will be LESS tailgating, not more -- I suspect something like a "braking distance + 50% safety factor" rule will be followed.

You already have vehicles that are heavily automated, like aircraft and metro trains, that COULD theoretically operate much closer. But good engineering dictates safety factors.

Submitted by AN on April 11, 2016 - 9:40am.

livinincali wrote:
AN wrote:
If every car is autonomous, I'm sure it would be safe for every car to be traveling at >100MPH, since they all will know where other cars around them are and where they're going, so there would never be any surprise.

It might be safe but it wouldn't be efficient. Cars traveling at 100+ mph use up a a lot more fuel/energy than a car traveling at 55 to 65 mphs. Autonomous cars should be able to draft better though.

As for high speed rail. I like the idea of it but I don't know that the cost of California's project is worth it. Last I heard the project was going to be over $100 billion. That just doesn't seem to be worth it.


What make you think it won't be efficient? Keep in mind the current power output and gearing is specifically designed for good performance response @<80MPH. However, if everything is fully autonomous, then there's no need to worry about throttle response. Then the gearing can be much taller and engine tuning can gear toward higher low end torque. Which would greatly increase efficiency at the detriment of throttle response.

Submitted by spdrun on April 11, 2016 - 9:47am.

Cars with 6, 7 speed transmissions or CVTs already have a tall top gear at detriment to throttle response. The issue isn't gearing at this point -- efficiency is limited by air, drivetrain, and road drag.

You might be able to gain efficiency by making cars lighter (lesser crash safety if they crash less), but above 80 mph, drag is mostly from air resistance. Frontal area isn't going to change much unless you start building 4-person autonomous motorbikes.

And if anything, autonomous cars will be even more bloated since people will want to stand up, eat, go to the toilet. Think of an 80s VW Microbus except scaled up 25% in all directions for fatties.

Submitted by AN on April 11, 2016 - 9:57am.

spdrun wrote:
Cars with 6, 7 speed transmissions or CVTs already have a tall top gear at detriment to throttle response. The issue isn't gearing at this point -- efficiency is limited by air, drivetrain, and road drag.

You might be able to gain efficiency by making cars lighter (lesser crash safety if they crash less), but above 80 mph, drag is mostly from air resistance. Frontal area isn't going to change much unless you start building 4-person autonomous motorbikes.

And if anything, autonomous cars will be even more bloated since people will want to stand up, eat, go to the toilet. Think of an 80s VW Microbus except scaled up 25% in all directions for fatties.


Average cars today still have drag co-efficient between .25-.35. They can totally reduce that to the high teens low 20s. Think Model 3. Regarding drive train, it's not about the amount of gear but about the gear ratio of the overdrive gear. Then there's the tuning of the engine. Think gas throttle response vs diesel gas mileage. If we no longer care about throttle response, then we can come up with engines like the turbo diesel that get awesome highway gas mileage at the detriment of throttle response.

Also keep in mind we're talking about varying degrees of efficiency, not absolute in-efficiency. I would take slightly less efficiency for the convenience of autonomous car over train any day of the week and on Sunday.

Submitted by spdrun on April 11, 2016 - 10:18am.

Personally, I'd rather take a train, assuming the train runs fairly frequently. Four hours stuck in a sensory deprivation bubble? Fuck that idea. I can get up, walk around on the train, eat something, piss, shit, meet people, all while in motion.

I DREAD a future where everyone is going from work to home to planned activities in their safe little boring self-driving bubbles of glass and metal. No unplanned human interaction. No serendipity. Just an ever more stratified society where people interact less and less with people who aren't like them. And turn into blobs of quivering adipose tissue while sitting in their auto-cages, which deliver them door-to-door. No walking, not even across a parking lot. If this will be the future, then I'm getting my fuckin passport ready to move to a less developed country when this comes to pass. I'll take my chances on a bicycle in a herd of tuktuks.

Drag coefficient might improve, but overdrive ratio is unlikely to improve much over modern transmissions, especially CVTs. We already have cars that can turn 1500-2000 rpm (the practical minimum without "lugging" risking bearing damage).

The future (IMHO) should be electric cars, not burning more fossil fools. Heavily automated trains (EVs with unlimited) range + limited-range electric cars would actually allow widespread adoption of both.

Submitted by Myriad on April 11, 2016 - 10:23am.

The current HSR plan is incredible stupid, expensive, and already over budget & behind schedule.
The train between SF and LA is a 50 year project. At the moment they should focus on buying the right of way and doing the EIS for the the entire line. The focus should be on the following regional HSR.
1. LA-LV
2. LA-SD
3. LA-Bakersfield 3a. SF-Oakland-Sacramento
As population expands and the rail is actually used, then the line can be extended to other cities.

At the current cost, it is already the world's most expensive rail program on a per mile basis, by a wide margin. It will likely be unsustainable and certainly won't make a profit (maybe not even on a operating basis - not paying back debt).

But this project is about political power even if the money would be better spent on regional rail, like a major rail system out of LAX.

Submitted by spdrun on April 11, 2016 - 10:32am.

Why not build the HSR using the I-5 ROW for significant portions?

PS- Vive la France:
http://marketurbanism.com/2012/07/10/wha...

Submitted by FlyerInHi on April 11, 2016 - 11:48am.

mike92104 wrote:
I think there will always be a combination of all of them.

I'm my opinion, technology will make dense urban living more attractive. Everything within walking distance.

http://youtu.be/UzKU9HR_Al8

Submitted by FlyerInHi on April 11, 2016 - 3:21pm.

spdrun wrote:
Why not build the HSR using the I-5 ROW for significant portions?

PS- Vive la France:
http://marketurbanism.com/2012/07/10/wha...

SNCF is cool. China Railways is even more impressive. I remember first visiting China before they had high speed rail. Now they have an awesome system.
https://www.youtube.com/watch?v=AFpnf5IrM5g

Submitted by spdrun on April 11, 2016 - 3:26pm.

China is having some teething problems with the same. SNCF is an established operator with a record of success. Wouldn't be the worst idea to give them the contract to build/run CAHSR.

Submitted by FlyerInHi on April 11, 2016 - 4:18pm.

spdrun wrote:
China is having some teething problems with the same. SNCF is an established operator with a record of success. Wouldn't be the worst idea to give them the contract to build/run CAHSR.

Kinda unfair.
China Railways has a better on-time record, and they manage systems around the world, including Denmark, I believe. They've come a long way.

And the Chinese system is clean -- more than can be said for France.

I hope they build the system between DC and Boston. Once people experience the lifestyle, they will love it. I love it that in Asia, you can just take the train to large shopping complexes. The stations are air-conditioned and connected to commercial centers. China does urban planning well. The central town square has a transport hub, hotel, bank, city hall, shopping, etc...

Submitted by spdrun on April 11, 2016 - 4:47pm.

I don't mind grit and dirt -- I might have been happier in the corrupt NYC of the 1970s.

DC-Boston could be sped up significantly in 4 years if they wanted to. Build a parallel set of tunnels to NYC from NJ, which would allow more trains to pass. Run some express trains between DC and Boston, with only a few stops. DC, Philly, Newark, NYC, New Haven, Boston come to mind, with none of the podunks in between. Get rid of the 30-minute stop in NYC, which has no good reason for existing.

The US doesn't need high-speed rail. It needs highER speed rail not run in a retarded fashion.

Submitted by svelte on April 11, 2016 - 6:49pm.

Public transportation has a long life ahead of it. autonomous vehicles will never be as inexpensive as public transportation.

Similarly, high speed autonomous vehicle roadways won't happen anytime soon. At least not in great numbers. Most all roads will continue to share the roadway between driver and driverless cars, and ya can't have super fast speeds with that combination.

What I'm waiting for is the super-traffic-jams when all autonomous vehicles decide to take the same path, get in the same lane, etc. Yeah sure they can program things otherwise in the long run, but in the near term I bet we see some really weird phenomena out there.

Submitted by FlyerInHi on April 12, 2016 - 12:11am.

spdrun wrote:
I don't mind grit and dirt -- I might have been happier in the corrupt NYC of the 1970s.

That's not high tech. You want gleaming air conditioned stations connected by shopping passes to commercial centers, hotels, residential complexes, and intermodal transport hubs where passengers can catch their Uber autonomous vehicles.

Think how advanced the sarineen terminal at jfk was when it opened in the 60s.
We need high tech, innovative stuff for the 21st century.

Submitted by spdrun on April 12, 2016 - 7:27am.

You're assuming I give a flying motherfuck about "high-tech."

Submitted by FlyerInHi on April 12, 2016 - 9:10am.

It's sad that Americans don't care about "high tech" anymore. Look at the space age central building at LAX that opened in the early 60s. We once had the best transport in the world. Now we are content with ordinary second best.

High tech is inspiring.

Submitted by FlyerInHi on July 27, 2017 - 1:37pm.

So China recently unveiled a second generation HS train just 6 years after starting the Beijing shanghai line. The train in clean, modern, and staffed with uniforms attendants like on airplanes.

Submitted by ucodegen on July 27, 2017 - 2:17pm.

Here are some interesting numbers:
TMPG - mpg to move 1 ton, or how many miles can you move 1 ton using 1 gallon of fuel.

Hybrid car:

  • Weight: approx 3000lbs (1.5 ton)
  • MPG: approx 50mpg @ 65 (less at 80 - engine running closer to limit of performance to gain mpg) less than 45mpg at 80.
  • TMPG: 75 tmpg

    Corvette: (its quirk is that it gets better mpg at 80 than 65.)

  • Weight: approx 3000lbs
  • MPG: 29mpg @ 80
  • TMPG: 43.5 tmpg

    Semi - loaded:

  • Weight: 60,000lbs (30t)
  • MPG: 7 - 10mpg - dealing with the newer ones.
  • TMPG: 210 tmpg using 7mpg.

    Train:

  • TMPG: over 400 tmpg - note, most rail runs around 80mph outside of cities.

    https://www.aar.org/newsandevents/Press-...

    It will be hard for cars, autonomous or not, to beat efficiencies of trains(provided that they are loaded). This included EVs and their claimed 100mpge.

  • Submitted by SK in CV on July 27, 2017 - 3:05pm.

    ucodegen wrote:
    Train:

  • TMPG: over 400 tmpg - note, most rail runs around 80mph outside of cities.

  • I don't think this affects the efficiency one way or another, but I just drove close to half way across the country and back, mostly on US 40. Probably saw 30 freight trains. Didn't see a single one much over 60 MPH. None were close to 80.

    Submitted by ucodegen on July 27, 2017 - 4:42pm.

    SK in CV wrote:
    ucodegen wrote:
    Train:

  • TMPG: over 400 tmpg - note, most rail runs around 80mph outside of cities.

  • I don't think this affects the efficiency one way or another, but I just drove close to half way across the country and back, mostly on US 40. Probably saw 30 freight trains. Didn't see a single one much over 60 MPH. None were close to 80.


    And you probably saw them near towns where the rail goes through..?? They do slow down on grades or when they have to pass. Most rail is single track, with sections that are dual to allow passing. They have to slow/wait on the passing sections. You can see that behavior down at the Sorrento Valley crossing. There are multiple tracks at the crossing, but outside of the crossing - the track drops to single track. Some of the recent work at the Sorrento Valley crossing was to add an additional track (in the event that two trains need to pass and there is a Coaster at the station loading) as well as making the paired track section longer (easier for freight passing).

    There is also a requirement to drop speed on tracks that don't have certain types of crossing and collision avoidance systems. See "Track classes" under this section:
    https://en.wikipedia.org/wiki/Rail_speed...

    Submitted by SK in CV on July 27, 2017 - 4:50pm.

    ucodegen wrote:
    SK in CV wrote:
    ucodegen wrote:
    Train:

  • TMPG: over 400 tmpg - note, most rail runs around 80mph outside of cities.

  • I don't think this affects the efficiency one way or another, but I just drove close to half way across the country and back, mostly on US 40. Probably saw 30 freight trains. Didn't see a single one much over 60 MPH. None were close to 80.


    And you probably saw them near towns where the rail goes through..??

    No, in the middle of f'ing nowhere. Which is pretty much the entire distance between Winslow, AZ and Oklahoma City.

    Submitted by ucodegen on July 27, 2017 - 5:32pm.

    SK in CV wrote:

    No, in the middle of f'ing nowhere. Which is pretty much the entire distance between Winslow, AZ and Oklahoma City.

    You mean Interstate 40 vs old US-40? US-40 is north of I-40 - both run east/west.

    Any town - even a little pip-squeak, ghost of a town can cause the rail to have to drop speed. Realize that if the train is going 80 in the same direction as you, you will probably not pass it and it will not pass you (if you are near 80 too). If in the opposite direction, it will be more of a blur, and passing a 2.6 mile long train would take less than 1 minute. Here is the info on passenger trains, note they try to run near max and the higher speeds to bias the results of the average.

    https://www.amtrak.com/national-facts
    see 4th bullet:

    More than half of Amtrak trains operate at top speeds of 100 mph (160 kph) or greater.

    https://www.quora.com/How-fast-does-a-pa...

    Submitted by spdrun on July 27, 2017 - 5:35pm.

    (1) Electrify the railroads.
    (2) Build new lines in the medians of interstates when possible. Grade separation already exists.
    (3) I think 80mph is legally possible for passenger trains with level crossings. In this situation, design the trains to accelerate as fast as possible to 80mph and the signaling system to keep them at max speed.
    (4) Or design "lethal" level crossing systems. Go around the gates, you'll find a spike strip like the "severe tire damage" device in parking lots waiting once you've gone through the crossing. If going around level crossing gates costs people a set of tires and a tow, fewer people would do it.

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