Why don’t more city transport networks use “through-routing”?

[M II A II R II K]

Why don’t more city transport networks use “through-routing”?


October 6, 2015

By Jarrett Walker

Read More: http://www.citymetric.com/transport/...h-routing-1455

Through-routing means that a route designed to carry people to or from a downtown doesn't end in the downtown; instead, it flows across downtown and out the other side as a different route.

- Some people are actually going from Connecticut to New Jersey, for example, and through-routing lets them make this trip without changing trains. More commonly, a lot of people from the north (i.e. Connecticut) are going to southern parts of New York City, while a lot of other people from New Jersey are going to northern parts of the city: a through-routed system serves both groups, which are briefly on the train at the same time in the city.

- Ending a line downtown means having facilities to store a bus or train for at least a few minutes, consuming expensive space. Trains typically reverse direction at an end-of-line station, so the driver needs to close her cab, walk the length of the train, and get herself set up on the other cab; she may also be entitled to some break time. A train occupies one of a limited number of tail tracks while this is happening, so this function becomes the limiting factor on the frequency of the whole line.

- The time it takes to turn a bus or train around, and provide the driver break, is usually not related to the length of the line. Through-routing two routes eliminates two ends-of-lines, which reduces the cost, both operating and capital, of those inefficient turnaround movements. Often, through-routing two lines actually reduces, by one or two, the number of buses or trainsets required.

- Sometimes, too, the pre-through-routed lines overlap in downtown, so the through-routing eliminates that overlap. Instead of having a bus dropping off passengers interacting with another bus picking passengers up, you have one bus dropping off passengers and picking them up at the same time. For buses especially, downtown street capacity is a very limited resource in big cities, and through-routing helps economise on it.

- There's never an exact one-to-one match between routes approaching from one direction and those approaching from the opposite direction. For example, San Francisco's downtown is on the bay at the northeast corner of the city – so there are no routes extending north and east that could be paired to routes flowing south and west. To the extent that such through-routes have been created (e.g. San Francisco's Muni Metro T line) the result is a circuitous approach to downtown for one of those lines.

- There are plenty of cases where through-routing would be in order but the two sides of downtown are different jurisdictional turf. They may be different states, as in New York, or different transit agencies. In the UK and Australia, they may be different private operating companies – and although both are government-subsidised, UK/Australia governments tend to defer to private companies about network design, so you often get designs that reflect company turf boundaries rather than efficient use of subsidies or meeting the needs of the customer.

- Your great-grandparents' jurisdictional barrier is often your infrastructure barrier, and New York City is the obvious example. Because each commuter rail line was designed by a separate entity, and each of these entities was thinking only about getting people into Manhattan, the terminal stations are not physically connected in the way you'd need in order for trains to flow through. This is the cause of most of the capital expense in Alon Levy's proposal for New York.

.....

Alon Levy's vision of New York area.







The Parisian RER network is one of the few suburban rail systems that does use through-routing.

[Crawford]

Philly does this, I think, with Septa regional rail.

The reason it doesn't generally happen in the NYC area is because you are talking totally separate transit agencies. There is some through-running for special events but not generally because you would have to coordinate across multiple state transit authorities.

[Mr Downtown]

The answer is usually history. Different companies, different unions, different equipment, different track or electric power. Institutional inertia can be one of the hardest things to overcome in transit.

Paris, Munich, Perth, and Philadelphia managed to do it, but few other cities ever did.

Bion J. Arnold's 1914 scheme for through-routing steam road commuter service through downtown Chicago is online here. It still makes a lot of sense to me:



Hooker, George Ellsworth. Through Routes for Chicago's Steam Railroads. City Club of Chicago, 1914

1. IC to C&NW North Line via a new subway under St. Clair and Ohio
2. Rock Island, NYC, and C&WI to C&NW Northwest Line via a new subway under LaSalle and Ohio
3. Alton, Wabash, and Pennsy to Milwaukee Road lines via Union Station
4. Burlington to C&NW West Line via Union Station

[emathias]

Originally Posted by Mr Downtown

...
Hooker, George Ellsworth. Through Routes for Chicago's Steam Railroads. City Club of Chicago, 1914

1. IC to C&NW North Line via a new subway under St. Clair and Ohio
2. Rock Island, NYC, and C&WI to C&NW Northwest Line via a new subway under LaSalle and Ohio
3. Alton, Wabash, and Pennsy to Milwaukee Road lines via Union Station
4. Burlington to C&NW West Line via Union Station

I agree. In fact that plan would still work today, with only minor changes:

1) IC to C&NW North Line via a new subway under Fairbanks and Ohio
2) Rock Island, NYC, and C&WI to C&NW Northwest Line via a new subway under Clark and Ohio
3) Alton, Wabash, and Pennsy to Milwaukee Road lines via Union and Ogilvey Stations
4) Burlington to C&NW West Line via Union and Ogilvey Stations[/QUOTE]

[M II A II R II K]

Toronto has through routing with it's subways and streetcars. Commuter Rail turns back at one station but could easily be through routed.

[fflint]

- There's never an exact one-to-one match between routes approaching from one direction and those approaching from the opposite direction. For example, San Francisco's downtown is on the bay at the northeast corner of the city – so there are no routes extending north and east that could be paired to routes flowing south and west. To the extent that such through-routes have been created (e.g. San Francisco's Muni Metro T line) the result is a circuitous approach to downtown for one of those lines.

The through-routing of Muni Metro trains has had an especially big impact on service into downtown during the morning commute. When I first moved to San Francisco, all inbound trains were either turned around or taken out of service at the busiest station, Embarcadero. At the peak of the morning commute, this meant delays. It was very common for trains to sit between stations for quite some time, waiting for room either at the platform or in the turnaround. When Muni dug a tunnel for the T Third line out the other side of Embarcadero, it allowed not only for through-routed trains but it also allowed Muni to turn trains around outside that station, which in turn means they can easily make enough room for inbound trains at the station. While many trains still turn around there, Embarcadero is no longer a terminal with a capital T.

[electricron]

Through routing of commuter trains requires passenger numbers traveling in the reverse direction all day long to make it worthwhile to pay the freight railroads for train slots to not only go in the reverse direction, but to return back to downtown for the afternoon commute.
Example:
Train A leaves end of line suburb station A and heads downtown at 0600. It arrives in downtown at 0700. It continues on in the reverse direction to the end of line station B. It arrives at station B at 0800. There the engineer/driver switches ends of train. Then ex-Train A, which from now on we'll call Train B, leaves end of line suburb station B at 0830. It arrives in downtown at 0930. At this point in time, this train can either continue on to suburb station A again, or remain parked and ready for the afternoon commute at the downtown station or yard.
Let's assume Train A was 10 cars long, and that as Train B it was 10 cars long too. Now that the morning rush should be over, at 0930, do we want to continue running it to station A as a 10 car long train? I would suggest the answer will be no. Until the afternoon rush, 2 or even 3 car long trains should be large enough to handle any traffic, assuming we wish to continue running trains all day.
Only a few trains on each line will be able to through run, depending upon the headways. If the line is single track with a few passing sidings, the reverse running Train A will likely be interring with the forward running trains between 7 and 8. Even in large cities with double track corridors, to reach the downtown station many lines are combined the last few miles. So a reverse running train could still be interfering with forward running trains.

Avoiding congestion is the reason why many commuter train operators don't through run. Those that do through run have spent additional capital to lay more tracks to minimize congestion. Commuter rail agencies already require a huge subsidy to run forward running trains that are basically full by the time they reach downtown, they would require more than twice the existing subsidy to through run and be almost empty by the time they reach suburb station B. So the obvious answer to your initial question is lack of money.

[scalziand]

Boston should have through running eventually with a tunnel between North Station and South Station, but it's going to take a while. Aside from the frustratingly large cost of the tunnel and portals, the commuter rail lines will need to be electrified too in order to run through the tunnel.

[mrsmartman]

New York City Subway has many through-routing services from Brooklyn via Manhattan to Queens/Bronx for its customers. Through-routing is often an ideal solution.

[ardecila]

Originally Posted by scalziand

Boston should have through running eventually with a tunnel between North Station and South Station, but it's going to take a while. Aside from the frustratingly large cost of the tunnel and portals, the commuter rail lines will need to be electrified too in order to run through the tunnel.

Not necessarily. MBTA could purchase dual-mode locomotives. Initially they would probably run trains from Providence to Gloucester, since the Providence branch is already electrified and Gloucester is the busiest north side branch. Ridership is roughly equivalent between the two, so they could maintain current service levels on both ends. Even if not all trains are through-routed, the tunnel still has utility because riders can transfer at Back Bay, South or North Stations to a train that does. Over time they would phase in through-routing service on other branches.

You maybe don't even need to electrify the tunnel at all. The Big Dig manages to exhaust plenty of cars and trucks from long underground tunnels. The SW Corridor in Boston already goes through a 1/2-mile tunnel south of Back Bay.

[tayser]

We're in a (long) process of reconfiguring the existing rail network to move more lines to through-routing.

Here's the way existing lines operate:



[all black lines on this map and one below are the regional services which run beyond Melbourne]

The City Loop (Flinders St / Southern Cross / Flagstaff / Melbourne Central / Parliament) has 4 individual single track tunnels which allow trains to turnback through a loop (not in and out reverse from flinders street).

All lines used to be associated with one track loop back in the 0s when the three underground stations opened (Flag/Melb Cent/Parly) but over come as frequencies have needed to be increased there hasnt been enough capacity so some lines have been progressively been taken out of the loop and run direct to Flinders Street - good examle is Sandringham on that ma above and Frankston only runs via loop in peaks but also has "shrot stopper" services which run direct and out to stations like Cheltenham (as there's triplicate track in this part).

This map is from 2013 proposals, much of them still on the cards but there are dramatic changes, this is a projection for in 20 years time:



Of the 4 city loop tunnels, only 2 will remain as a loop-turnback. the other two tracks are going to be reconfigured so that they become a track pair for a North-South Line (yellow) which is the existing Craigieburn and Frankston lines.

The blue line is a completely new track pair right through the middle of the city - that's the Melbourne Metro project (all the planning / approvals is getting done now and with a new PM who loves PT in Canberra now, likely to get funding - woo!) - and it's going to combine 3 existing lines (Pakenham/Cranbourne and Sunbury) and provide space for 3 more branches - but in effect it's going to be a massively long line - near on 100km from Pakenham to Sunbury.

The two tracks over the viaducts infront of the CBD which wont be part of the loop-turnback structure that currently exists (thanks to the yellow line now just running through the track pair in tunnels around the edge of the cbd) will be re-used to through-route the Alamein and Glen Waverley lines to the South West lines/branches.

And the Grey line - Mernda (currently runs as far as South Morang) will have a new tunnel from Clifton Hill to Fishermans Bend built - which conceivably (And should) reach Newport at least for connectivity to the west - essentially taken one branch from an exsiting loop-turnback and through-routing it across the city.

The deep purple line will be another north-south line - using for the most part existing track - just with some new flyovers / reconfiguring in the inner north of the city.

There are 4 stages (last map is the 4th stage), you can see the sequencing across all the phases here: https://urban.melbourne/forum/ptvs-n...ropolitan-rail

[NorthernDancer]

Originally Posted by M II A II R II K

Toronto has through routing with it's subways and streetcars. Commuter Rail turns back at one station but could easily be through routed.

Some of the Lakeshore West trains are through-routed to the Lakeshore East line and vice versa.

[scalziand]

Originally Posted by ardecila

You maybe don't even need to electrify the tunnel at all. The Big Dig manages to exhaust plenty of cars and trucks from long underground tunnels. The SW Corridor in Boston already goes through a 1/2-mile tunnel south of Back Bay.

Back Bay Station has horrific ventilation issues from all the diesel exhaust from the trains in the tunnel. The Central Artery tunnel has lots of exit ramps that help with ventilation. The rail tunnel is going to be even deeper under the highway tunnel, with no big openings like the highway ramps.

A study published last year by the Boston-based Clean Air Task Force found that the air quality on Platforms 1, 2, and 3 at the Back Bay station, as well as in stairwells and the waiting area leading to those platforms, was being sullied by exhaust from the diesel engines used by the MBTA commuter rail trains.

The task force visited the station in late 2006 and then again this past April. "The air was horrible," said Bruce Hill, a senior researcher. "The air was many, many times below air-quality standards." Soot levels measured during the studies were "off the charts high," in some cases greater than could be measured by the devices being used by researchers, he said.

http://www.boston.com/news/local/art...to_fix_t_says/

Air quality hasn't improved since then, although the new tier 4 diesels the MBTA is getting might help with that.

Getting closer to the thread topic, 2 of the 4 rapid transit lines are already through running, and the underconstruction Green Line extension will make that line through running too, helping to balance service patterns.

[mrsmartman]

Opposite to the through train model, when all trains go to the same terminal:


MTA Commuter Rail Lines, 1979 by Otto Vondrak, on Flickr

[blackcat23]

Los Angeles is currently working on two projects which will enable through routing in Downtown.

http://www.metro.net/projects/regionalrail/scrip/"]http://www.metro.net/projects/regionalrail/scrip/[/URL]

SCRIP, which is scheduled for completion in 2019, will add run-through tracks to the south end of Union Station. This will allow Metrolink and Amtrak trains to pass through the station, rather than being forced to enter and exit through the same five-track throat at the north end.

It will cut travel times approximately 15-20 minutes and increase Union Station's capacity up to 50%.


http://www.latimes.com/local/la-me-u...528-story.html

http://www.metro.net/projects/connector/

The Regional Connector, which is already under construction, will create a new subway between the busy 7th Street/Metro Center Station and Little Tokyo. It will merge the Blue, Gold and Expo Lines into a north-south route between Long Beach and the San Gabriel Valley and an east-west route between Santa Monica and East Los Angeles.


http://www.ladowntownnews.com/news/m...9bb2963f4.html

[Pink Jazz]

I always heard this being referred to as interlining. Some of the bus routes here in the Phoenix area do this. In my dream light rail system for the Phoenix area, I would have two pairs of lines that would do this - the Orange and Brown Lines at Chandler Fashion Center, and the Pink and Purple Lines at Superstition Springs Center.

Note that for interlining to be effective, the destination signs should be changed prior to the arrival at the transfer point, otherwise some people may board the wrong train/bus. My dream light rail system would do that exactly by GPS, and would use multicolor LED destination signs to make the lines easily identifiable.

[Swede]

Originally Posted by Pink Jazz

I always heard this being referred to as interlining. Some of the bus routes here in the Phoenix area do this. In my dream light rail system for the Phoenix area, I would have two pairs of lines that would do this - the Orange and Brown Lines at Chandler Fashion Center, and the Pink and Purple Lines at Superstition Springs Center.

Note that for interlining to be effective, the destination signs should be changed prior to the arrival at the transfer point, otherwise some people may board the wrong train/bus. My dream light rail system would do that exactly by GPS, and would use multicolor LED destination signs to make the lines easily identifiable.

Interlining requires that the lines are kept as seperate lines with seperate identities while through-running does not. I don't think I've seen interlining in Europe. IMO interlining doesn't make sense when there's decent headways and the connecting point is well used. Just use one name/number for the whole line.

[scalziand]

I kind of wish that the WRTA bus routes in Worcester were through routed instead of all terminating at the downtown hub, but it'd probably be harder to dispatch the lines if they through ran.

[mrsmartman]

NORTH SOUTH RAIL LINK



MAP OF EXISTING COMMUTER RAIL SYSTEM, WITH NO CONNECTION BETWEEN NORTH AND SOUTH. [© BRAD BELLOWS ARCHITECTS]



Map of unified system, with all commuter rail and transit lines connected in downtown Boston. [© Brad Bellows Architects]

http://www.northsouthraillink.org/

[fflint]

Originally Posted by mrsmartman

NORTH SOUTH RAIL LINK



MAP OF EXISTING COMMUTER RAIL SYSTEM, WITH NO CONNECTION BETWEEN NORTH AND SOUTH. [© BRAD BELLOWS ARCHITECTS]



Map of unified system, with all commuter rail and transit lines connected in downtown Boston. [© Brad Bellows Architects]

http://www.northsouthraillink.org/

This is a wonderful concept, but is there any chance whatsoever this will come to pass? Boring several tunnels under the already-existing Boston subway system would be extraordinarily expensive.