Why the loop? (Chicago, Cicero, Evanston: transfer, legally, train)

[metrosaurus]

I am curious to get some insight about why Chicago's 'L' runs in a loop downtown and most other major US transit systems (Boston, NYC, DC, Philly, etc...) don't use a similar loop in their downtown areas. Is this because of something different about Chicago or just a preference of those who designed the transit system here? What are the practical advantages and disadvantages of Chicago's "loop system" compared to other transit systems such as the ones I listed?

[Link N. Parker]

I think there are historical reasons for this; when the system was designed, it was designed with the idea that the centrally-located Loop district was the hub for the city and that a lot of workers either worked there, or would need to pass thru there in order to go to their jobs (at factories etc).

Actually the Loop gets its name from the circular route that the El train forms as it encircles the business district.

[chet everett]

There are "rail buffs" that run nice sites explaining all about this -- Chicago ''L''.org: History - The Original ''L'' Lines

[paytonc]

All trains need to turn around once they get to their destinations. The Loop remains a great way to do this: it simultaneously turns the trains, without any downtime, while also distributing the passengers around downtown.

Most newer systems, including Chicago's Red & Blue Line subways, are "through-routed": trains go through downtown, emerge on the other side of town, and get turned at the other edge of town. One quirk about Chicago is that the "L" franchises were awarded such that each company only ran trains on one side of town -- they were legally prohibited from running trains past downtown. Hence, the Union Loop was the most elegant solution to a bunch of "L" lines that all needed to turn trains around downtown.

There are other systems that use a loop arrangement to turn trains and/or distribute passengers; the Yamanote Line in Tokyo comes to mind.

[emathias]

Originally Posted by Link N. Parker

...
Actually the Loop gets its name from the circular route that the El train forms as it encircles the business district.

Well, actually actually, they Loop was named originally for looping streetcar tracks. The elevated loop came later.

[Chicago60614]

Originally Posted by paytonc

All trains need to turn around once they get to their destinations. The Loop remains a great way to do this: it simultaneously turns the trains, without any downtime, while also distributing the passengers around downtown.

Most newer systems, including Chicago's Red & Blue Line subways, are "through-routed": trains go through downtown, emerge on the other side of town, and get turned at the other edge of town. One quirk about Chicago is that the "L" franchises were awarded such that each company only ran trains on one side of town -- they were legally prohibited from running trains past downtown. Hence, the Union Loop was the most elegant solution to a bunch of "L" lines that all needed to turn trains around downtown.

There are other systems that use a loop arrangement to turn trains and/or distribute passengers; the Yamanote Line in Tokyo comes to mind.

This says it. The original companies operated single lines and not the entire system. They shared the loop, but then they went back to their starting point on the tracks they came in on. For the most part they couldn't continue out the other side on someone else's tracks.

There is actually talk about changing this. For instance combining the Orange and Brown Lines into one line.

[chirack]

Originally Posted by Chicago60614

This says it. The original companies operated single lines and not the entire system. They shared the loop, but then they went back to their starting point on the tracks they came in on. For the most part they couldn't continue out the other side on someone else's tracks.

There is actually talk about changing this. For instance combining the Orange and Brown Lines into one line.

The companies merged and by the 20ies the CRT was formed then through route became possible. What is now the brown line was called the Ravenswood and at times it was through routed on to the old Kenwood line(gone, and part of the south side lines). Intrestingly enough Lake street didn't through route until the Dan Ryan was made. Basically the Englewood/Jackson Park through routed with a northside line. Another intresting point is that the Original lines kept their sub-terminals(where they stoped before the loop) until the 40ies/50ies! The loop when built reached capacity and they used the sub-terminals to offload some traffic.

In the late 60-90ies there was the Lake-Dan Ryan now it is the Green line(and does the Englewood andJackson park intead of Dan Ryan).

The Dan Ryan retains the ability to go over the loop instead of the subway if needed.

[chirack]

Originally Posted by metrosaurus

What are the practical advantages and disadvantages of Chicago's "loop system" compared to other transit systems such as the ones I listed?

The big downside of the loop(or really EL tranist in general) the downtown focus. Almost all Chicago El lines run downtown. Which can make certian cross town trips less efficient(Trips that go north/south away from the loop). Only the yellow line never goes downtown and it is really just a shuttle between Skokie and Howard Street(the north border of Chicago). The purple line too acts like a shuttle between Wilmete/Evanston and Howard(outside of Rush hour).

There has been talk about adding a circle line but it is not happening at the moment. It would allow trains to go north/south without going through downtown. It would also connect with all the other lines outside of the loop allowing more efficent transfers for people who don't need to head so far east into the loop. It would likely be done in stages once they seatle on where to put it(Chicago's denesity drops as you head away from downtown but so do land costs). Cheapest place and densest would be down Ashland only trouble is that Ashland isn't that far away from the loop. The other place would be Westren but costwise that is more(and currently less favored) however it would be a nice distance from the loop.

[Alacran]

Originally Posted by chirack

The big downside of the loop(or really EL tranist in general) the downtown focus. Almost all Chicago El lines run downtown. Which can make certian cross town trips less efficient(Trips that go north/south away from the loop). Only the yellow line never goes downtown and it is really just a shuttle between Skokie and Howard Street(the north border of Chicago). The purple line too acts like a shuttle between Wilmete/Evanston and Howard(outside of Rush hour).

There has been talk about adding a circle line but it is not happening at the moment. It would allow trains to go north/south without going through downtown. It would also connect with all the other lines outside of the loop allowing more efficent transfers for people who don't need to head so far east into the loop. It would likely be done in stages once they seatle on where to put it(Chicago's denesity drops as you head away from downtown but so do land costs). Cheapest place and densest would be down Ashland only trouble is that Ashland isn't that far away from the loop. The other place would be Westren but costwise that is more(and currently less favored) however it would be a nice distance from the loop.

Cicero

[Kamms]

Originally Posted by metrosaurus

I am curious to get some insight about why Chicago's 'L' runs in a loop downtown and most other major US transit systems (Boston, NYC, DC, Philly, etc...) don't use a similar loop in their downtown areas. Is this because of something different about Chicago or just a preference of those who designed the transit system here? What are the practical advantages and disadvantages of Chicago's "loop system" compared to other transit systems such as the ones I listed?

All of the cities listed got rid of the elevated trains in the CBDs. I've stated this before, the "L-loop" design is 1890s transportation design and needs to be removed. Keep the section on Van Buren and turn it into a high-line type park. This way the history of the line remains in a different way and 21st century transportation designs can be implemented. The loop elevated train lines need to be removed.