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Old March 6th, 2013, 09:02 PM   #1161
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Sure trams in congested areas should have right of way (shared with busses or even taxis in less intensely congested areas), likewise where there are no trams busses/BRTs should have right of way in congested areas.

Not only will trams/busses stuck in traffic mean slower and less attractive alternatives to cars (which would add to traffic in those areas), it also means that the costly trams and busses are less efficiently used. Right of way in those cases mean faster service with higher frequency. Win-win.
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Old March 6th, 2013, 09:11 PM   #1162
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^those trams act more like mass transit than the old streetcars. if the city is big enough/traffic bad enough, even ROW/priority signalling/etc. don't help much.

thus in these situations, might as well construct completely grade separated mass transit. people may complain about the distance between stations, but a solution would be to have more maneuverable feeder buses and parallel transit lines.
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Old March 6th, 2013, 09:44 PM   #1163
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That's why my argument
Low density ♥ busses, minibusses, bicycle taxis
Metro (medium-long distance) + tram (medium-short distance) = ♥

The multi-lane streets of Beijing makes right of way for trams/busses fairly easy. In the narrow historical core of many European cities ROW means that those streets are effectively closed for car traffic.

Grade separation means that the cars are isolated from other traffic, but at a significant transfer cost for the passengers to get to the underground/elevated station. A neat trick could be to integrate elevated metro with local tram, but that is not an alternative around the CBD or other dense regions of Beijing.

(Again, I haven't looked at cost. A small tram network is expensive to run, but gets benefits of scale if larger.)
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Old March 6th, 2013, 10:29 PM   #1164
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your solution would be more suited for the suburban areas or smaller cities. this whole convo started over a crazy assertion--congested central beijing needed a streetcar system.

unfortunately beijing is especially large, and has high density too. closing off the streets will just direct more traffic to the remaining arterials, resulting in even worse traffic. those service vehicles will still remain and will waste even more time/pollute even more/clog up the streets even more. then you'll want (and need) grade separation at intersections. beijing is more akin to paris or new york than it is to vienna or other central european cities.

would an at-grade tram work efficiently in central paris? manhattan?
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Old March 6th, 2013, 10:42 PM   #1165
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You can ride your bicycle faster than the speed of a european tram. In other words, China will increase their productivity by going back to bicycles ratehr than spending millions upon milloins on last millennium museum pieces. Yes, I despise trams! Light rail on the other hand can be sexy!
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Old March 7th, 2013, 09:54 AM   #1166
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Quote:
Originally Posted by particlez View Post
your solution would be more suited for the suburban areas or smaller cities. this whole convo started over a crazy assertion--congested central beijing needed a streetcar system.

unfortunately beijing is especially large, and has high density too. closing off the streets will just direct more traffic to the remaining arterials, resulting in even worse traffic.
Again, it is the very densest urban areas we are talking about. Few places are denser than the Beijing CBD, especially as planned for the future, and it is not a crazy assertion. I am not convinced it is a good idea, but for other reasons than density.

But first maybe some definitions because the last comment ("trams bad, light rail good") made me wonder if we are talking about the same thing. I don't want to quarrel about the particulars, classification of vehicles on rail is about the most boring topic on the planet, but in this case trams = light rail. None of us want the quaint historical tourist-friendly cars you can find in Hong Kong. I use Wikipedia here for definitions.
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A tram (also known as a tramcar; a streetcar or street car; and a trolley, trolleycar, or trolley car) is a rail vehicle which runs on tracks along public urban streets (called street running), and also sometimes on separate rights of way.
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Light rail or light rail transit (LRT) is a form of public transport using a steel-tracked fixed guideway that operates primarily along an exclusive right of way and has vehicles capable of operating as a single unit or as multiple units coupled together.
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A right of way is a type of easement granted or reserved over the land for transportation purposes, such as for a footway, carriageway, trail, driveway, rail line or highway. [For a tram discussion we mean exclusive, no cars allowed, right of way]
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Grade separation is the method of aligning a junction of two or more surface transport axes at different heights (grades) so that they will not disrupt the traffic flow on other transit routes when they cross each other.
You can have trams that are not light rail, and vice versa, but that is not what we're interested in. And with metro I mean a (sub)urban public mass transport train system at any grade, just like in Beijing. The other words, like subway, tend to imply a particular grade. Metro might be light rail, but here we're talking heavy rail.

With that out of the way, trams/light rail is good at moving people. They move more people than busses can, and more comfortable too because they move along predetermined tracks. (I could imagine computer-asssisted busses, with the computer providing the "track", but those things don't exist yet.) They are also more energy efficient, tracks beats wheels. Cars is the worst alternative for throughput at high density and low speed (very few people on a large area), but beat pedestrians and bicyclists on higher speed (they can be densely packed, but don't move fast). They never beat busses, trams, or metro, assuming they have a reasonable occupancy rate. Even a tram without right of way stuck in traffic with the rest will move a lot more people than the cars they are stuck with will.

Getting into the Central Business District would best be done with metro (supplemented with busses, cars, tram lines for that matter), and not at street grade (tunnels or elevated). Getting around in the CBD would best be done with busses or trams with right of way at street level, supplemented with cars where the throughput need is not too high, taxis for the rest. If the CBD were designed like Toronto it could be below street level, if it were like Hong Kong it could be elevated (forgetting cost), but Beijing CBD is neither so local traffic should be at street level.

I am not sure trams will beat busses, but if the transport need is really high they would. My biggest concern would be that a tram breaks down or is blocked, so is the whole line until the obstacle is removed. With a larger network you can reroute, with a smaller network you would need high reliability. That comes at a cost.
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Old March 8th, 2013, 07:00 AM   #1167
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You mentioned ROW. ROW =/= Grade separation. ROW in the densest areas is still compromised by pedestrian crossings, slow-running/stopped trams in front, turning wheeled vehicles, vehicles stuck in intersections, etc. The Hong Kong tram is a good example of ROW's limits. Those trams are definitely slower than the buses on the street, and sometimes slower than the pedestrians. By the time you talk about grade separation, you're moving into the realm of mass transit. Trams =/= mass transit. Thus, you might as well have short haul feeder buses + expansion of grade separated mass transit.

Trams will NOT beat buses in areas like Central Beijing (or any other similarly large, similarly congested area). They look quaint, and can carry a lot of people, but are still hindered by every obstacle in the way. The bus can actually move around obstacles.

Thus if you're going to advocate for tramways (with ROW but without grade separation) in central Beijing, you might as well argue for tramways in the busiest, most congested parts of Paris, Tokyo, Manhattan, etc. It's not going to work. How many trams do you see in these places? Yet the buses can still function in the most congested areas.
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Old March 8th, 2013, 07:06 AM   #1168
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the funny thing is, you mentioned that the trams will beat buses if the transport need is high. eh.. there are several factors involved.

-increasing demand for higher capacity will favor trams
-congestion will favor buses

it's a big reason why trams (without grade separation) do not fare well in the centers of large, congested cities.
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Old March 10th, 2013, 10:18 AM   #1169
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Beijing and Shanghai metro ridership set new record on March 8th

Beijing: 10.276 million
Shanghai: 8.486 million

by 上海轨道交通俱乐部
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Old March 10th, 2013, 10:48 AM   #1170
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how about other cities then?
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Old March 10th, 2013, 02:59 PM   #1171
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Quote:
Originally Posted by particlez View Post
You mentioned ROW. ROW =/= Grade separation. ROW in the densest areas is still compromised by pedestrian crossings, slow-running/stopped trams in front, turning wheeled vehicles, vehicles stuck in intersections, etc. The Hong Kong tram is a good example of ROW's limits. Those trams are definitely slower than the buses on the street, and sometimes slower than the pedestrians. By the time you talk about grade separation, you're moving into the realm of mass transit. Trams =/= mass transit. Thus, you might as well have short haul feeder buses + expansion of grade separated mass transit.
Hong Kong trams have no ROW, and have no relevance here. If you look at the total travel time, it is the time to get to the station, average waiting time (inverse of frequency), the travel time station to station (including transfers), and time to get from station to your destination. For surface transport the major component in Beijing is the time from station to station, stuck in traffic.

Except the airport line, the 6 line, and future express lines, the Beijing metro doesn't go very fast, the distance to the nearest station is usually large, getting from the entrance to the train takes a long time (3-5 minutes, but some are quicker), and the transfer time/distance can be atrocious, but the frequency is high, and crucially there are no traffic jams. All in all metro is the best bet for getting to the Central Business District. But it is a poor choice for moving around inside the CBD.



Look at the CBD segment of the metro map for 2015 above. The CBD isn't particularly big, but metro is unlikely to be a mode of choice most trip within the CBD. It is too slow and too inconvenient. You would have to go to the nearest metro station, travel down to the platform, and likely transfer once or twice, all of which involve significant walking and add to the travel time.

A tram/LRT or BRT with right of way would be affected by traffic and chaotic driving, even traffic lights, but I would assume that the route they travel will have priority at traffic junctions, and the trams/busses priority lights at that. For major junctions they could be grade separated as necessary.

A bigger issue would be wait at the bus/tram stops. Some time will be lost by acceleration, but more by the time passengers use exiting and entering. Low floors, more doors, and wider doors will help the flow (though that may mean that the Yikatong would have to be on the honours system). Buses can run an express/local scheme with fewer/more stops, that is harder to achieve with trams.
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Old March 10th, 2013, 08:10 PM   #1172
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Originally Posted by Bannor View Post
You can ride your bicycle faster than the speed of a european tram.
What??? European trams "fly" up to 80 km/h...
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Old March 10th, 2013, 09:04 PM   #1173
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Hong Kong trams have no ROW
They actually do. Just that it's pretty meaningless when the path is blocked most of the time. Thus taking the Hong Kong Island tram is a pain during the weekdays, but actually makes sense late at night.

The Beijing subway is compromised, but the solution to the issues is more subway lines and stations. Again, the urban planners aren't stupid. The system itself has not yet been completed. Apart from cost, there is no actual disadvantage to building more mass transit.

-the demand exists
-there are gaps in coverage

Quote:
A tram/LRT or BRT with right of way would be affected by traffic and chaotic driving, even traffic lights, but I would assume that the route they travel will have priority at traffic junctions, and the trams/busses priority lights at that. For major junctions they could be grade separated as necessary.
A local tram/BRT circulator has its purpose, but it will not alleviate the overcrowding on the existing lines, and unless it has full grade separation, it will get bogged down in the mess of local traffic. If you're going to have grade separation over the messy intersecting vehicular/pedestrian traffic, you might as well...

There are fiscal conservatives who have argued against further subway expansion. They say cheaper alternatives can do the job more efficiently, and have even pointed to __________ streetcar city as an example. I really hope your editorial isn't influenced by them. BTW, the editors at Caixin serve more as lobbyists than as independent journalists.

Arguing for a streetcar > subway in central Beijing just doesn't make sense. "If" central Paris and Manhattan had Beijing's existing half-completed system and its gaps in coverage, would you advocate for subway expansion, or would you argue for lower capacity, sometimes at-grade streetcars?
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Old March 10th, 2013, 09:38 PM   #1174
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Originally Posted by _Night City Dream_ View Post
What??? European trams "fly" up to 80 km/h...
Here in Amsterdam some trams have an average speed of about 16-18 km/h. Their max speed is 70 km/h, but because of at-grade crossings, other traffic, etc., speed is often limited to 50 km/h. Most time lost is in the old city center.

Considering Paris metro's have an average speed of 20 km/h, the trams aren't performing all that bad, but on my bicycle I also get an average of 16-19 km/h in the old city center, so for me the tram is pretty useless.

Last edited by Silly_Walks; March 10th, 2013 at 09:44 PM.
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Old March 10th, 2013, 09:43 PM   #1175
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Can't Beijing have moving walkways to fill the gap between metro stations? Beijing's sidewalks are very wide, and moving walkways can bring people to places that are in a gap of subway coverage.
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Old March 11th, 2013, 12:38 AM   #1176
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Then again the tram system in the old town of Amsterdam is the quintessential of quaint, it gets to the Central Station eventually, but by the least efficient mode possible. It is the only tram system I know of where trams share a single track in both directions, a track they share with pedestrians (a good portion of which are stoned tourists).
image hosted on flickr


The Beijing CBD, an area of maybe 2km x 3 km depending how you count (the CBD proper is even smaller, more like the London Square Mile). It is far away from "Beijing Old Town", a couple decades ago it was country-side, and has a Beijing-style grid system. A city block can range from 200m x 200m to 800m x 800m, there are not that many street crossings along a main artery, though each crossing is huge.

I assume most traffic in the CBD is to/from a destination there, or bypassing traffic (particularly the 3rd and 4th ring road and the Jingtong radial) where the CBD is only an obstacle. Even so, that leaves a significant amount of short distance traffic (the longest possible trip would be around 3.5 km) involving a large amount of people.

Let's set up three scenarios:

The distance between metro stations is a little over 1 km on average. The biggest highrises cluster around those station, so the average distance to nearest metro station should be around 400m. That is 5 minutes at average walking speed, it will take an average of 3 minutes from the station to the platform or transfer, and 2 minute wait for the next train, and the train spends 1 minute at each station. Let's assume that a typical trip would be 2 stops with one transfer, and average speed of 50 km/h between station. This trip would be 19 minutes walking, 3 minutes waiting, and 3 minute traveling for a total of 25 minutes total traveling time.

The bus/tram scenario assumes more stations for 200m distance to the nearest station, 1 minute to enter/exit platform, 3 minute average wait, 1 minute to enter bus/tram, no transfer, but the route is twice as long as a straight line would be (4 km instead of 2 km), and a travel speed of 20 km/h. This passenger would spend 8 minutes walking, 3+8 minutes waiting (8 minutes at stations on the way), 12 minutes traveling for a total of 31 minutes travel time.

The silly_walkway scenario would install moving walkways along all major roads. You would walk an average distance of 100m to a walkway entrance, spend a minute accelerating, another minute switching to a perpendicular walkway, and finally walk 100m to the destination. The distance would be 2 km at 8 km/h. The total would be 2.5 minutes walking to/from walkway, 3 minutes entering/transferring/exiting, and 15 minutes walking on walkways for a total of 20.5 minutes walking time.

Silly_walkway is thus the winner in these scenarios (cost, maintenance and other practical considerations not included. Interestingly enough it does not involve more walking than the metro scenario.

A denser metro scenario, with half the distance to the nearest station, would have shaved off 5 minutes from walking time (but added 2 minutes to travel time because of the extra stations). A more efficient entrance-to-platform and tranfer design would achieve the same saving without adding travel time, or the cost of doubling the number of lines.

The bus/tram scenario involves the least walking, but this scenario with a bus/tram route covering most locations like above isn't very efficient either. Better use something more like what is used in Beijing today, more bus lines going more direct with more targeted stops. This would add to time waiting for bus, possibly with a transfer, but would reduce number of stops and travel time. This can be done with trams too, but less efficiently.
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Old March 11th, 2013, 01:06 AM   #1177
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^funny your 3 scenarios ignores the most efficient one:

actually laying new grade separated lines. the demand for mass transit outstrips the present lines' capacity, and there are gaps in service. don't cheapen out with at-grade service and allow cross-traffic t impede it.

the higher capacity of trams (vs. buses) is compromised when cross traffic is in the way of the tram. the presence of cross traffic is a reason why ultra high density, ultra congested hong kong's island line uses double decker vehicles. even then, its practicality is up for debate.

if someone is going < 1km, it makes more sense to walk, or take a flexible, short haul bus. the beijing cbd will eventually have a subterranean walkway system.
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Old March 11th, 2013, 01:15 AM   #1178
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Quote:
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Then again the tram system in the old town of Amsterdam is the quintessential of quaint, it gets to the Central Station eventually, but by the least efficient mode possible. It is the only tram system I know of where trams share a single track in both directions, a track they share with pedestrians (a good portion of which are stoned tourists).
image hosted on flickr
Well, the tracks aren't really shared with pedestrians... they're exclusive to the trams. But it's not illegal to cross the tram tracks

I looked it up, and the average speed of trams in the city center is about 10-12 km/h


For Beijing, at least in/near it's center, I don't think they should go for trams while they still have money for subways. Trams are obstructed by and themselves obstruct other traffic too much.

I was kind of jokingly mentioning moving walkways, but in Beijing's wide, grid-pattern streets and long station distance, they could actually fill a gap efficiently.
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Old March 11th, 2013, 04:53 AM   #1179
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Can't Beijing have moving walkways to fill the gap between metro stations? Beijing's sidewalks are very wide, and moving walkways can bring people to places that are in a gap of subway coverage.
Just let the pedestrians walk! Gee, we sit on our asses long enough nowadays, at least let people walk from the subway to their offices.
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Old March 11th, 2013, 05:51 AM   #1180
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Just let the pedestrians walk! Gee, we sit on our asses long enough nowadays, at least let people walk from the subway to their offices.
I'm saying exactly that they should walk... but that walking can be sped up to make subways even more efficient by increasing their effective catchment area.
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