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Well, you should have used the original schematic of the M1. Then the norht would have been up and the line would have flow in the correct direction.


Paris' Metro and it's tires... it's a long story. It goes back to the first round of modernization of the network back in the 50's. There is now 5 lines in Paris (if we forget about Matra's - now Siemens - VAL) that uses this very technology developed by the RATP for it's performance in tractative power.

Aaron M. Renn

Yes, those of us here in the states who suffer hearing loss from riding the Chicago L and such are painfully aware that Paris subways run on rubber wheels.

I rode the Line 14 many times when I was making trips to one of the less fashionable districts of Paris. It's a great line. It will be nice to see the rest of the system upgraded like that.


I think the weight is on tires for acceleration and braking, but I think there are also two steel rails underneath with steel wheels on the train for guidance, plus the horizontal guidance on top. It's always been weird to see the steel rails complete with normal rail switches, together with the concrete paths for the rubber tires.

The rubber-tired lines in Paris are far hotter in the summer than the normal steel rail lines - I've always believed due to all the extra friction of rubber tires on concrete. It must increase the energy consumption of the rubber-tired lines.


Jeez...they transport that many people and they are only using 6 car trains? The pictures I have seen of the line never show more than a handful of people standing up. What kind of frequency are they running...120 tph?!?!?

Alon Levy

With 213 million annual passengers, Line 1 breaks even with the average subway line in Moscow, Seoul, and Tokyo. It's behind Line 1 in Shanghai, Singapore's two older lines, and probably some lines in Osaka and Hong Kong.

The rubber tires increase energy consumption, yes. The friction coefficient of steel on steel is much lower than that of rubber on concrete or asphalt. That's why trains have a much easier time than cars achieving high speeds, and a much harder time achieving fast acceleration and braking rates. This tradeoff carries over, and for low-speed operations like metros, rubber tires have way better performance, but consume more energy and are higher-maintenance.


Could you run a vehicle with wheels like those on rails through downtown, then in a BRT-style fanout after leaving the tunnel?

Jarrett at HumanTransit.org

@Ezra.  No, the metro vehicle is precision designed around the rails.

@Danny.  The "six-car train" is really a single car with six articulated segments.  It is the same length as the train platform.   I doubt they'll get to 120 trans/hour, but I expect 90 is possible. 


Also, the tires have to be inflated with nitrogen, rather than air, because the heat will occasionally cause them to explode. The train will run on a steel wheel instead of the tire then, but an air-filled tire would have an increased risk of catching fire, and tires produce exceptionally noxious smoke. Also, rubber-tired subways don't handle snow at all well, to the point where Montreal's system is 100% covered, including not just all mainline trackage but also all yard tracks, siding, the whole lot of it.

Peter Smith

The friction coefficient of steel on steel is much lower than that of rubber on concrete or asphalt.

i assume the 'friction coefficient' you were referring to was the 'rolling resistance coefficient' (or 'rolling friction' or 'rolling drag') as opposed to the '(sliding) friction coefficient' -- implying, i guess, that the rolling resistance is where most energy/efficiency is lost, as opposed to slippage and squealing from the steel-on-steel wheels during acceleration, braking, turning, rain, leaves, etc. Sounds reasonable to me.

i suspect both friction coefficients go up in magnitude when going from steel to rubber, but i'm not sure how closely they are related. i'd be curious to see some numbers. couldn't find any after a quick bit of googling.


@Danny: Paris métro is quite a small loading gauge. Trains are 2m40 wide and line 1 (like line 4 and 14) use 90m long six-car trains. This six-cars are nothing comparable to the usual New York or Japanese subway rolling stock. A train can hold up to 720 people.

Its astonishing numbers mostly come from the fact this line is runing along Paris' msot major axis. It connects together it's most important business and touristic/entertainment centers. That alones make the M1 particularly attractive for Parisians and tourists. It's the ever busy line, trains run on a tight schedule and they always are full. It's never empty and the fluxes are quite well distributed. The M1 is some sort of transit planner dream come true.

That said, if you haven't seen it packed and full it's because you never saw pictures or video taken during rush hours. On this line, even the last metros are usually packed with people going back home on week days.

If I'm not mistaken, at rush hours the minimum head way on the line must be something around 100 or 105 seconds and the automation of the line should bring that number down to 90 or 85 seconds.

Alon Levy

Peter: yes, I meant rolling resistance. Sorry.

Anonymouse: you're right that rubber-tired metros don't handle snow well. But the newer implementations have mostly gotten over this. The Montreal Metro uses old technology, so it has to be fully underground; newer rubber-tired systems, such as the Lille Metro, do go above ground.

Samussas: the automated line 14 has a minimum headway of 120 seconds. However, it's not as busy as 1, and the technology may be capable of higher frequency.


@Alon: The minimum headway on line 14 is 100 to 110 seconds during rush hour peaks. Your numbers must went back before the last round of service reinforcement (2009). The 14th is getting busier and busier. I think it has a daily ridership of around 450.000 since the last expension far from the record of the M1 but still, at rush hours the M14 is at capacity between Chatelet and Gare de Lyon.


The climate in Lille isn't too different from that of Paris, and Paris has plenty of above-ground sections on the rubber tire lines. There are other examples from further north: Sapporo has a line with an elevated section, but it's covered along its entire length. There's also the airport shuttle system in Chicago, which uses the same VAL technology as Lille and is uncovered, but I have no idea how well it works in the snow. Given that airports and roads leading to them tend to close when there's a lot of snow falling, I suspect it just doesn't matter, but the elevated tracks look like they'd at least be easy to clean.


I'm going to be visiting Paris next month and my hotel is near Tulleries. I was going to take the Metro from Gare du Nord to my hotel but I was told that M1 stations don't always have elevators so it may be difficult with luggage. Can anyone here give me some idea how difficult it will be to navigate Paris Metro with my luggage?

Andy K

What would it take to make BART driverless - from a technical stand point only. If I understand correctly, the operators only control the doors, and the slow speed sections (less than 10 or 15 mph).

Jarrett at HumanTransit.org

Bzcat, lifts and escalators have been added in major stations but it's very hard to do this everywhere in the historic metro, but the station detail maps do show where they exist.  You will find much more abundant lifts and escalators in the urban part of the RER system, and of course on the new Metro Line 14.   If your trip is not on the RER, I suggest you do the last bit by taxi.


From a technical standpoint, BART drivers open and close doors and run the trains in yards as well as in manual mode on the mainline when that's called for. Making it driverless would imply some difficulty with things like people falling off the platforms as well as restricted employee access to the track.

Alon Levy

Bzcat, I carried luggage from Gare de Lyon to Porte de Vincennes on Line 1, but it involved dragging a suitcase down staircases and having it noisily bang against every stair. It's the same way I carry luggage on the New York City Subway, if that means anything to you.


"Eventually, the line will feature automated doors on the platform"
yes, but it will not allow air conditioning of the platform. platform door will be mid height, to effectively prevent intrusion, but not to high for reason of perceived comfort.
(see picture at http://fr.wikipedia.org/wiki/Automatisation_de_la_ligne_1_du_m%C3%A9tro_de_Paris )
also note that full separation of tunnel and station (required for air conditioning) could create some air pressure issue (the train acting as the piston of an air compressor in the tunnel, and the station is needed as an air reliever: notice the wind when the train arrive: this air has to go somewhere).

It is interesting to notice that Paris subway train are narrower (2m40 vs 2m65) than the Vancouver Skytrain, and have not much longer platform (80m vs 90m), so in fact could present same floor area (Canada line train merely 30% less, ~150), what can be indicative Vancouver skytrain potential whether its lines was seeing the Line 1 traffic pattern (probably average trip not longer than 3km, where the one on skytrain is 10km, so a Paris line 1 seat serves 3 times more customer than a skytrain one)...

I will attend your talk at Vancouver SFU (may be you will recognize me ;)


Toronto's TTC is about to receive delivery of a fleet of new subway trains that are of a similar design -- the current six-car trains will be replaced by continuous trains with articulations separating the train into six sections. However they will be longer than the Paris trains -- about 150 metres total length, or about 25 m per car.

They're intended to increase passenger capacity on the TTC's busiest line (Yonge), in part because the articulations can be used as additional passenger standing space, but also because passengers can move down the train to balance capacity utilization throughout the train. (Southbound trains leaving a major transfer point at Bloor station during the AM peak period are often packed in the rear cars, corresponding to the location of the corridor to the east-west line, and underused in the front cars.)

This will also have the side effect of making it easier for riders to exit the train through the door closest to the station exit -- currently this requires that you preplan at your boarding station, which is not always possible if the train arrives just as you reach the platform.

Daniel Sparing

The horizontal wheels are also rubber, plus the vertical steel guidance wheels (standard rail) as mentioned.

Roberto Remes

Mexico City subway lines 1 & 2 reached 1.1 million passengers per day in 1989, they are now around 900 thousand per day. Guangzhou BRT line 1 transport around 800 thousand passengers per day, and is only surpassed by line 2 of Beijing subway (I don't have data about this line). So, Paris Line 1 is not the busiest subway line in the world. Nevertheless this automation is an example about how to improve a subway line and how to increase its capacity.

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