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Elon Musk's Vegas Loop... Debunking.

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boffin:

--- Quote from: wraper on June 12, 2021, 06:45:19 am ---
--- Quote from: boffin on June 12, 2021, 03:42:34 am ---Also the fanboys that are saying "But it will eventually do 120mph"

Science & Math:

120mph = 53m/s = let's call that 50m/s for simplicity
0 to 50m/s in let's say 10 seconds (which is really fast), or an acceleration of 5m/s² (½G) - very uncomfortable as a passenger, and impossible if you're sitting sideways
Distance traveled during 0 to 50m/s =   ½at²   =   0.5 * 5 * 10 * 10 = 250m

The tunnel is about 650m between stations, so that's

* 10 seconds ½G accel (250m)
* 3 seconds at top speed (150m)
* 10 seconds ½G deceleration (250m)
--- End quote ---
For sceptics, 120 mph is a figure for longer tunnels  :palm:. At no point of time there was any claim that existing segment will operate at 120 mph. So all you math does is fighting a straw man.

--- End quote ---

No, the fan boys are still saying 120mph; even Vegas press are touting 155mph still for 'the loop' at the LVCVA.


The LVCVA itself said:

"...The innovative transportation system will allow convention attendees to be whisked across the LVCC’s 200-acre campus in just over one minute -- free of charge -- in all-electric Tesla vehicles capable of holding between 3 and 16 people..."
https://press.lvcva.com/Events/las-vegas-convention-center-makes-history-as-elon-musk-s-the-boring-company-begins-tunneling-the-des/s/a313340f-1f36-4dd7-a53b-76c399215586

"Just over a minute" to: start, accelerate, decelerate, slow to 15, accelerate, decelerate, stop, for 8/10ths of a mile (1.3km); and that's assuming not stopping in the middle.  If you watch people's videos of this actually with real traffic from this week, you can already see the central station is a bottleneck, and cars waiting in the tunnel to enter.



To give you another idea of how dumb it is, there are crosswalks, blocking the loop traffic to get into the south and west stations; yes the loop comes to a complete stop when someone wants to get into the area where you board and disembark his rolling advertising.




--- Quote ---
--- Quote ---Oh, and as I've mentioned in another post, that 4400 number is actually 4x the normal pphpd number used to measure regular transit systems.
--- End quote ---
Isn't the number 2 times too high?

--- End quote ---

No, he's counting A-B and B-C simultaneously in each direction.
Firstly transit systems are not measured from each station, but the  line as a whole (so that's 2x)
Secondly, transit systems are measured per direction.  (that's another 2x).


If I tried an 'elon math' on one of our local transit system lines (Expo Line, 19 stations/18 segments, 500 person trains leaving every 90 seconds/40 tph, in both directions)
you'd get 720,000 people per hour   (500 * 18 * 40 * 2)

In reality, the number (in civil engineering pphpd) is 500*40, or 20,000 pphpd



Did I mention our local system is driverless and has been for 35 years?

wraper:

--- Quote from: boffin on June 12, 2021, 07:35:07 am ---No, he's counting A-B and B-C simultaneously in each direction.
Firstly transit systems are not measured from each station, but the  line as a whole (so that's 2x)
Secondly, transit systems are measured per direction.  (that's another 2x).

--- End quote ---
I don't think it's true. You take a ride to where you want, there are no intermediate stops. So it can be A to B, B to C or A to C.

boffin:

--- Quote from: wraper on June 12, 2021, 07:43:13 am ---
--- Quote from: boffin on June 12, 2021, 07:35:07 am ---No, he's counting A-B and B-C simultaneously in each direction.
Firstly transit systems are not measured from each station, but the  line as a whole (so that's 2x)
Secondly, transit systems are measured per direction.  (that's another 2x).

--- End quote ---
I don't think it's true. You take a ride to where you want, there are no intermediate stops. So it can be A to B, B to C or A to C.

--- End quote ---

A-C passes through B, it's not a triangle.

Let's show it another way.  Station B, in the middle, capacity 5 cars in any direction
car unload/load time = 45 seconds (rough guess)
car every 9 seconds, 400 cars/hour
3 people per car = 1200 persons/hour;
which is oddly close to my 1100 number.

Face it, you don't want to hear it, but in this case Elon has sold them snake oil.





nctnico:
I guess most people don't get that it is a demonstrator. Not something that is actually useful. However, having a public transport system which is able to transport people more directly from A to C without going through B can be a major improvement in time.  The reality is that underground transport systems can easely be outperformed using a simple bicycle (let alone an electric bicycle). The effective speed of underground public transport is really low. In that perspective Tesla's Vegas loop is an interesting idea but obviously it needs lots of improvement.

wraper:

--- Quote from: boffin on June 12, 2021, 07:56:55 am ---A-C passes through B, it's not a triangle.

--- End quote ---
Based on what info do you assume that 4400 people per hour figure does not include a significant number (like a half) of A to C and C to A rides? And all rides are from/to B.

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