Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[DJ]

I can think of no very good reason why robot taxis wouldn't have better coverage than other forms of mass transit.

Road traffic in every major city centre is slow as molasses. Cars are simply ridiculously space inefficient compared to subways.

[10ebbor10]

Anyway, remember that the autotaxis are electric powered. That does reduce their range a bit.

[forsaken1111]

I can think of no very good reason why robot taxis wouldn't have better coverage than other forms of mass transit.

Road traffic in every major city centre is slow as molasses. Cars are simply ridiculously space inefficient compared to subways.

And yet people continue to prefer cars over subways because efficiency isn't as important to many people as flexibility.

[Sheb]

Cars and subway serves different areas and different needs. They are complementary, and so will subways and electric cars.

[10ebbor10]

I can think of no very good reason why robot taxis wouldn't have better coverage than other forms of mass transit.

Electric power means reduced range, if you're not operating in the city center.

Most other reason rely on legislative reasons and the government being annoying, which it will be .

[DJ]

I can think of no very good reason why robot taxis wouldn't have better coverage than other forms of mass transit.

Road traffic in every major city centre is slow as molasses. Cars are simply ridiculously space inefficient compared to subways.

And yet people continue to prefer cars over subways because efficiency isn't as important to many people as flexibility.

Not really. When I was visiting relatives in London we took the tube everywhere we went, even though they had a car, because the tube is 3-4 times faster even when it's not rush hour.

[forsaken1111]

And yet people continue to prefer cars over subways because efficiency isn't as important to many people as flexibility.

Not really. When I was visiting relatives in London we took the tube everywhere we went, even though they had a car, because the tube is 3-4 times faster even when it's not rush hour.

I can only really speak to what I have personally observed, but here taking the tube/subway is only really viable if you are going into the city. As a large city, I wouldn't expect London to be any different.

In no way will a taxi service replace the subway. I'm not sure why this is even an argument. All I've said is that a taxi service can take you to many places that a subway can't. If you like the tube, keep using it. I like being able to go to places that aren't near a tube station.

And the sheer volume of car traffic tells me that people ARE indeed using cars over tubes, whatever you might say.

[Sheb]

Electric power means reduced range, if you're not operating in the city center.

Most other reason rely on legislative reasons and the government being annoying, which it will be .

Not all robotaxis would be electric. It's would be fairly easy for a large robotaxi operator to have a fleet composed of various vehicles, from small electric 1-seater pod to minibus running on gas.

As for car over tube, I agree with forsaken. Everywhere I go, I see people using car 10-30m over the tubes lines.

[LordBucket]

tl;dr:
Subways are stupidly expensive, and they only make sense in places where population density makes it impractical for surface roads to accommodate the required traffic. Don't complain about couple hundred million a year road maintenance costs if you're spending multiple billions a year subsidizing your rail industry that cost over ten times as much to build in the first place than similar lengths of road.

Autotaxis outcompeting subways: This won't happen - once all the commuters who previously used public transportation use autotaxis, the streets will be so crowded during the rush hours that the subway will be faster once more.

@Cost of building subways: Streets need to be built too, you know...

I don't know where you live, but personally, the nearest subway to me is roughly fifty miles away and I'd have to drive on a five lane freeway to get to it.

remember that the autotaxis are electric powered. That does reduce their range a bit.

Yes, at present 100 to 150 miles of range, which means 3 to 6 hours of operation. By comparison, the LA metro rail is 87 miles long. Which means they would have better range than subways.

Also, remember you don't own these vehicles. They're taxis. There would be nothing stopping you from getting out of one and into another. Whereas a rail line physically ends, and once you reach the end...you're done. Taxi clearly beats rail here.

Streets need to be built too

Common sense would tell us that a road is vastly cheaper than a subway. If common sense fails, let's look up numbers.


http://money.cnn.com/2012/05/31/news/economy/nyc-subway-construction/

"$4.5 billion for the first mile-and-a-half segment. With three stops and a new entrance to an existing station, the cost of construction is more than a billion dollars a stop."

http://pedestrianobservations.wordpress.com/2013/06/03/comparative-subway-construction-costs-revised/

 * "Singapore Downtown MRT Line: S$20.7 billion for 42 km: $493 million/km."
 * "Sao Paulo Metro Line 6: 7.8 billion reais for 15.9 km: $250 million/km"
 * "Mexico City Metro Line 12: $1.8 billion for 26.4 km. After PPP conversion, this is $90 million/km.
 * "Barcelona Sants-La Sagrera tunnel: built 2008-11, €179.3 million for 5.8 km: $39 million/km."

So, routinely hundreds of millions per kilometer, and the cheapest one on the list is dozens of millions per kilometer.

How expensive are roads?

http://www.artba.org/about/transportation-faqs/#20

Construct a new 2-lane undivided road – about $2-$3 million per mile in rural areas, about $3-5 million in urban areas.
Construct a new 4-lane highway — $4-$6 million per mile in rural and suburban areas, $8-$10 million per mile in urban areas.
Construct a new 6-lane Interstate highway – about $7 million per mile in rural areas, $11 million or more per mile in urban areas.

Subways are between one and two orders of magnitude more expensive than roads. Also, multiply that by 1.6 because miles are longer than kilometers.

Not to mention they need require maintenance per year

No.

http://www.orange.nsw.gov.au/site/index.cfm?display=329376

"It is currently estimated that the average life span of a Road Pavement is approximately 39 years"

http://www.brighthubengineering.com/concrete-technology/45858-concrete-roads-vs-asphalt-roads/

"Concrete roads have a long service life of forty years, whereas asphalt roads last for ten years. "


As for actual costs:

http://www.sacog.org/mtp/pdf/MTP2035/Issue%20Papers/Road%20Maintenance.pdf

"Caltrans is spending $2.4 billion statewide for state highway maintenance and rehabilitation this year"

2.4 billion/yr to maintain the highways for the entire state of california

http://www.dot.ca.gov/hq/tsip/hpms/hpmslibrary/hpmspdf/2010PRD.pdf

City streets: 75,207 miles
County roads: 65,166 miles
State highways: 15,159 miles

So, 2.4 billion dollars a year to maintain 15,159 miles of highway. In comparison:

http://en.wikipedia.org/wiki/Transport_in_the_United_Kingdom

"The National Rail network of 10,072 route miles (16,116 km) in Great Britain"

http://dataportal.orr.gov.uk/displayreport/html/html/bfee944f-5d61-42ee-a4ad-df41d02ef567

"Government subsidy towards the railway industry in 2012-13 was £5,060 million (£5.1 billion),"

So Great Britain is paying 5 billion/yr for 10,000 miles of rail, and California is paying 2.4 billion/yr for 15,000 miles of highways.

Yes, this is not a perfect comparison. The population of Britain is about 65% higher than california. And, different countries. Some things are likely to be different. But California is spending roughly half as much money subsidizing 50% more length of road as Britain is subsidizing rail. Also at less than one tenth the initial construction costs, and with vastly more route flexibility.

If you want a same state comparison:

http://en.wikipedia.org/wiki/Expansion_of_Bay_Area_Rapid_Transit#San_Jose_subway_extension_.28Phase_2.29

"The originally-planned complete extension from Fremont to Santa Clara was projected to cost $6.1 billion, but the VTA estimates the extension to Berryessa (Phase 1 only) would cost just $2.1 billion"

That's eight billion dollars for approximately 11 miles of track. For the cost to build 11 miles worth of San Fransisco rail, we could have maintained all 15,000 miles of California state highways for over three years.



If you're in Tokyo, yes...robot taxis might have a difficult time replacing subways. But we're talking about the US, and here they make vastly more financial sense than rail.

[forsaken1111]

Thank you LordBucket.

[10ebbor10]

In cities were subways operate, you have to include land costs.

[andrea]

If you live 50 miles away from the nearest subway station, autotaxis won't outcompete subway for the simple reason that they aren't competing in the first place. They exist to service areas of high population density. They will lose a share to autotaxis, but probably not that much, due to traffic issues.
They will however compete much more directly against cars, especially in suburban areas in which mass transport isn't convenient nor efficent.

[Sheb]

I wonder what's the throughput in terms of person/hours for a subway lave vs. road though. Also, while roads are cheaper to build, subways are cheaper to run. If you're going to compare subway vs. robotaxi, you need to take into account running cost and the buying of all those taxis.

[10ebbor10]

I wonder what's the throughput in terms of person/hours for a subway lave vs. road though. Also, while roads are cheaper to build, subways are cheaper to run. If you're going to compare subway vs. robotaxi, you need to take into account running cost and the buying of all those taxis.

Taking the London underground, one of their more modern trains can take 1553 passengers per train. ((In practice probably higher, but ability to overcrowd isn't part of this comparison)).

Now, by comparing some timetables, it appears the average time between trains is between 2 to 10 minutes, most often 5.

So, metro line  is about 18 000 people/hour (45 000 is we run trains using a mere 2 minute delay).

Now, calculating road capacity is a bit harder. Assuming that the gap (between cars) + car take about 5 meter, and that traffic proceeds at a gentle speed of 50 km/h* without stopping, then a single lane road can transport 10 000 cars  per hour. Which considering most taxis will only pick up 1 passenger, seems quite accurate. However, the average car in London only makes 15 km/h. So, about 3000 cars per hour.

*Like that happens in a city.

[DJ]

I think 15kmh is a bit generous when you consider just how many stoplights there are in a city.