Center Island vs. kerbside platforms

[Myrtone]

This has been discussed a bit in another related thread, but I now realise that it belongs in its own one. Unidirectional streecars like those in Toronto and Philladelphia, and in Pittsburgh (before being converted into LRT, mostly with high platforms), require all stops being located on the right hand side, which is the kerbside of all two-way streets in North America. Among legacy systems, even New Orleans seems to have platforms/access only on the right, judging from photos and footage I've seen. Was this generally the case with first generation systems in North America, whether uni or bidirectional running was used? Yet newer systems, even the essentially street based Portland streetcar has platforms on both sides. In light of the practice on legacy systems, one wonders whether island platforms make sense in the street enivroment. First of all, stops on many four lane roads are necessarily on the kerb side. Given that most newer systems have platforms on both sides, is equipment provided to make sure that doors are opened on the platform side, and if not, have there been any cases of drivers opening the wrong doors?
Furthermore center island platforms require slewing of rails and overhead wires, and in fact, slewing tracks around offset side island platforms actually takes up less lateral space that do center island platforms, the latter also requires greater slewing of tracks.
If a stop is located in a cutting or on an embankment, or if there is an elevated or underground walkway where the stop is located island platforms allow for sharing vertical access between both sides, rather than being duplicated or available on only one side. But on a street based system, stops of that sort are exceptions, and, for all we know, they could be in locations where it is easy to arrange for one direction to passover the other, and thus could run on the left where island platforms are useful, thus making island platforms possible where needed, even with doors on only the right.

[TomNelligan]

Among legacy systems, even New Orleans seems to have platforms/access only on the right, judging from photos and footage I've seen. Was this generally the case with first generation systems in North America, whether uni or bidirectional running was used?

The wonderfully historic New Orleans system, most of which runs in a wide median strip between the highway lanes (locally known as the "neutral ground") has platforms on both sides of the cars. The St. Charles line has platforms on the right side in the direction of travel, but Canal Street is mostly left side/center platforms once out of the central business district, as is the new Loyola extension. The private right-of-way Riverfront line uses island platforms with car doors opening on the left.

But to answer your general question, North American legacy systems generally used right side (or curbside) entry and exit whether street running or on private right of way. There were a few exceptions -- like some island platforms in the Boston trolley subway that required left-hand doors on all cars then and now -- but center or island platforms were not common practice.

[Myrtone]

The wonderfully historic New Orleans system, most of which runs in a wide median strip between the highway lanes (locally known as the "neutral ground") has platforms on both sides of the cars. The St. Charles line has platforms on the right side in the direction of travel, but Canal Street is mostly left side/center platforms once out of the central business district, as is the new Loyola extension. The private right-of-way Riverfront line uses island platforms with car doors opening on the left.

I do suppose the St. Charles street line is older, I remember reading about the reopening of the Canal street line, did the original Canal street line have all stops on the right?

But to answer your general question, North American legacy systems generally used right side (or curbside) entry and exit whether street running or on private right of way. There were a few exceptions -- like some island platforms in the Boston trolley subway that required left-hand doors on all cars then and now -- but center or island platforms were not common practice.

I gather than Boston only has left side platforms in the underground section, and such stops do require access from above, often directly so, which is easier with island platforms. This raises the question of why they don't arrange for one direction to pass over another, if they ran on the left in that tunnel, they wouldn't need doors on the right, and thus more (fixed front facing) seats.
So if North American legacy systems, whether unidirectional or bidirectional, generally used right side (or curbside) entry and exit whether street running or on private right of way, have you wondered why most new systems, even street based ones often have some platforms on the left side?

[electricron]

MATA in Dallas, whether using single or double cabs trolleys, requires doors on both sides. Curbside running is preferred so passenger can be picked up and dropped off protective from traffic using existing sidewalks. When running in the center of the street (using old historic tracks) it uses right side doors providing passengers no protection within the street because there are no island platforms. When running curbside on new tracks in the right lane it uses right side doors to provide passenger protection, BUT when running curbside on new tracks in the left lane it uses left side doors to provide passenger protection. Believe it or not, MATA uses left lanes slightly more often than it uses right lanes. So all the trolleys need doors on both sides.
The purpose of my reply so far is to suggest that trolleys may need doors on both sides when running curbside, you cannot assume the trolleys will be using only the right lanes, especially on one ways streets.
The soon to be Oak Cliff streetcar in Dallas will be using double cab modern streetcars with doors on both sides because it will be using single track initially. There will be short double track segment at a station/stop with an island platform at startup that may or may not require using doors on the opposite side of the train than all the other stops, depending upon which side of the platform the streetcar uses. BUT they are planning on having a loop on one end of the line in downtown Dallas when extended, turning the train in the loop will require doors on both sides, no matter which lane is used in the loop.
The purpose of the latter part of my reply is to suggest you can't assume anything - double or single track, loops or not, curbside platforms or island platforms, platforms or no platforms. Any streetcar line can have all.

I.E., A design decision made for any segment of a streetcar line doesn't have to apply to the entire line.

[nomis]

I gather than Boston only has left side platforms in the underground section, and such stops do require access from above, often directly so, which is easier with island platforms. This raises the question of why they don't arrange for one direction to pass over another, if they ran on the left in that tunnel, they wouldn't need doors on the right, and thus more (fixed front facing) seats.

Boston underground: has two stations with islands that feed the same direction of travel, at Kenmore and Park. Also Haymarket is setup as a center island serving both directions of travel. (Park even has a track that opens both sides for boarding/alighting). Goverment Center is designed as one big triangle island with all left handed stations. North Station is one track stacked on top of the other, both boarding from the same overall direction. If you ran wrong track main, your still faced with stations on both sides requiring doors on both sides.

Above ground: Riverside is the only station [terminal] that I can think of that routinely boards/alights when trains change ends in the station. Cars short turn, and cross over to the opposite side above ground, such as E trains short turning at Bringham Circle. Boston has bidirectional cars since they both change ends and loop depending on where they're going.

[F-line to Dudley via Park]

I gather than Boston only has left side platforms in the underground section, and such stops do require access from above, often directly so, which is easier with island platforms. This raises the question of why they don't arrange for one direction to pass over another, if they ran on the left in that tunnel, they wouldn't need doors on the right, and thus more (fixed front facing) seats.

Boston underground: has two stations with islands that feed the same direction of travel, at Kenmore and Park. Also Haymarket is setup as a center island serving both directions of travel. (Park even has a track that opens both sides for boarding/alighting). Goverment Center is designed as one big triangle island with all left handed stations. North Station is one track stacked on top of the other, both boarding from the same overall direction. If you ran wrong track main, your still faced with stations on both sides requiring doors on both sides.

Above ground: Riverside is the only station [terminal] that I can think of that routinely boards/alights when trains change ends in the station. Cars short turn, and cross over to the opposite side above ground, such as E trains short turning at Bringham Circle. Boston has bidirectional cars since they both change ends and loop depending on where they're going.

There are also some ex-streetcar quirks forcing that. The bi-level bus tunnel at Harvard Square is unusual in that one level requires left-handed boarding, which is why the T's trackless trolleys are unique in North America for having left-handed middle doors. Diesels do use that tunnel and require an awkward squeeze around the bus to board. Used to be a trolley tunnel, and since the entirety of the Boston Elevated Railway's fleet had to be compatible with the Central Subway whether assigned to a subway-feeding carhouse or not, they have all been universally equipped with left-handed doors for the last 115 years. Hence, wasn't any big deal for them to build a collector/distributor tunnel at Harvard with a left-handed level...until they had to start running buses through it.


Don't know if there were any other surface routes that boarded on the left side. I know Mass Ave. in North Cambridge has always had that center median even when the Harvard trolleys were running on the 77 route, but they still boarded right-handed in the middle of the street.

[Literalman]

The Greater Greater Washington blog had an interesting discussion last week of side versus island platforms: http://greatergreaterwashington.org/pos ... platforms/

[ExCon90]

My recollection may be getting hazy here, but in Cleveland the Shaker Heights Rapid Transit occupied an open-air depressed right-of way immediately after leaving Public Square and had island platforms because each stop was reached by a stairway down from the street which crossed overhead. They ran left-handed in this territory so that the right-hand doors could be used, and one track crossed over the other just before reaching Shaker Square, after which normal right-hand running was used. When the Rapid was built, it ran left-handed in the same territory, with high-level side platforms at stations served by it, the Shaker Heights platforms of course being of normal streetcar height. Now that the PCCs are all gone I don't suppose it matters, but I'm sure they still run the same way.

[Myrtone]

MATA in Dallas, whether using single or double cabs trolleys, requires doors on both sides. Curbside running is preferred so passenger can be picked up and dropped off protective from traffic using existing sidewalks. When running in the center of the street (using old historic tracks) it uses right side doors providing passengers no protection within the street because there are no island platforms. When running curbside on new tracks in the right lane it uses right side doors to provide passenger protection, BUT when running curbside on new tracks in the left lane it uses left side doors to provide passenger protection. Believe it or not, MATA uses left lanes slightly more often than it uses right lanes. So all the trolleys need doors on both sides.
The purpose of my reply so far is to suggest that trolleys may need doors on both sides when running curbside, you cannot assume the trolleys will be using only the right lanes, especially on one ways streets.

Are bicycles and motor vehicles required to stop when passengers are boarding and alighting the trolleys on the right hand side. I don't see how, anywhere in North America, you could run kerbside in the left lane, except on one way streets.

The purpose of the latter part of my reply is to suggest you can't assume anything - double or single track, loops or not, curbside platforms or island platforms, platforms or no platforms. Any streetcar line can have all.

And any heavy rail line can have them all too. But with street based systems, experience appears to favour side platforms in the street enviroment for three reasons; Access to the stop is from the same (floor) level, not above or below. There is often not enough room for center platforms on four/two lane two-way roads. And island platforms, while possible on wider roads, do often require slewing of tracks, and slewing tracks around staggered side island platforms conserves more lateral space.

A design decision made for any segment of a streetcar line doesn't have to apply to the entire line.

And even it's looped at both ends and rolling stock only has doors on the right, different design decisions can still apply, the two I can think of are left-hand running with center island platforms and right-hand running with side platforms.
Some stretches may have directional running, where the two directions following different streets, this being a feature of round-the-block looping. If there are, whether or not it's part of a loop, one might put the entrance to an underground section on the left-hand side, and thus can quite easily keep left in the tunnel, without crossing over at the portal.

[Myrtone]

The Greater Greater Washington blog had an interesting discussion last week of side versus island platforms: http://greatergreaterwashington.org/pos ... platforms/

I saw that discussion, but it's a discussion about side versus centre island platforms on underground heavy rail, not on light rail, let alone street running. Mixing island and side platforms is quite normal on heavy rail lines, and (metro) trains always have much higher seating capacity than streetcars, even with doors on both sides and cabs at both ends. Most of the factors they mention aren't relevant to a street based system, except sometimes on reserved track sections.

In the street environments kerbside platforms are usually more efficient because homes, businesses, etc, served by the stops are also on that side on the same level, not above or below. The kerbside is on the right everywhere in North America, except on one way streets where both sides are each the kerbside, and narrower (two way) roads don't have room for island platforms anyway. And even when it does, offset side-island platforms do require less lateral space.

On reserved track sections, influencing factors are the same as for all other surface rail, however, while street track everywhere in North America (with the possible exception of pairs of tracks following different streets) demands right hand running, this does not have to also have to apply to private right of way as long as one track can easily pass over another. And while single track sections seem to be quite rare on both surviving legacy systems and on new build ones, any single track section, at least on dedicated right of way, can have both left and right hand passing loops.
Hence factors influencing streetcar stop layout usually favour platforms on the right hand side except where there is a specific requirement, such as running kerbside in the left lane of a one way street.

[Disney Guy]

Most if not all "legacy" light rail systems had the tracks in the center of the street with (in North America at least) all right side boarding. Most also had double ended cars at first, so the car interior space required for doors on both sides was a given. Before there was a lot of faster automobile traffic, there were no safety islands so the overall street width did not need to be wider at the passenger stops. Had island platforms been used back then, street width would have had to be increased from the git go.

Legacy systems with all right side boarding (the vast majority), if they went to single ended cars, purchased cars with doors on only one side, giving more interior space for seating. This sometimes forced unusual construction or operational techniques (e.g. Cleveland).

It was rare for tracks to be re-laid in the street to provide an island platform where none was originally. The space sharing concept, requiring motorists, on the right, to stop for boarding and alighting passengers, continues at some locations in some cities as opposed to having a 24/7 dedicated space i.e. a safety island or an island platform, for passengers.

Island platforms were used a lot in subways and on elevated structures where arrangement of stairways and fare collection areas would be simpler compared with side platforms. Provided that rush hour passenger loads were not heavy in both directions at the same time, an island platform narrower than the combined width of side platforms might also be possible.

[Myrtone]

Most if not all "legacy" light rail systems had the tracks in the center of the street with (in North America at least) all right side boarding. Most also had double ended cars at first, so the car interior space required for doors on both sides was a given. Before there was a lot of faster automobile traffic, there were no safety islands so the overall street width did not need to be wider at the passenger stops. Had island platforms been used back then, street width would have had to be increased from the git go.

What do you mean by island platforms, side or central? A platform between two track (for opposite directions) is a central island platform, a side island platform is between one track and one half of the road.

Legacy systems with all right side boarding (the vast majority), if they went to single ended cars, purchased cars with doors on only one side, giving more interior space for seating. This sometimes forced unusual construction or operational techniques (e.g. Cleveland).

And judging from photos I've seen, they also had most seats facing forward, did passengers generally prefer to travel forwards? The technique in Cleveland, still in existence today in Gothenburg on the outer section of the line to Angered, seems to have been a case of not seeing a reason to adopt left hand boarding on just one section of track. Why bother buying new rolling stock or rebodying existing vehicles with additional doors on the left (just for a few central island stops) if you can easily arrange for one track to pass over another and still have doors on only the right gives you more seats per car, these being directly opposite the doors?

It was rare for tracks to be re-laid in the street to provide an island platform where none was originally. The space sharing concept, requiring motorists, on the right, to stop for boarding and alighting passengers, continues at some locations in some cities as opposed to having a 24/7 dedicated space i.e. a safety island or an island platform, for passengers.

You surely wouldn't have needed to re-lay tracks in the street just to provide a side island (platform). Only central islands require that, as they require an increase in track centers. Offeset side islands either don't require that, or, to save lateral space, require both tracks to be slewed a tad around each platform. And I don't suppose that legacy operators saw any reason to have central islands in the street enviroment.

Island platforms were used a lot in subways and on elevated structures where arrangement of stairways and fare collection areas would be simpler compared with side platforms.

Simpler arrangement of vertical access (mostly stairways and elevators) is the only real advantage of central island platforms over side ones, and this factor is not usually relevant to street stops. The aforementioned section of Gothenburg tram track (originally intended to be a metro line) has each track in a separate tunnel, quite widely separated such that central island platforms did not require any track slewing, typical of bored tunnels. This section of track is shared by routes 4, 8 and 9 (towards Mölndal, Frölunda and Kungssten) yet the two directions cross at grade, which I imagine would create a bottleneck. The complex of tunnels that Cleveland reportedly used could not create any such bottleneck.