Skip-stop
The skip-stop or skip-stop (German literally stop-omit , analogous to operation with alternating stops ) is a form of operation in public transport with regular service , in which the stops on a route are served alternately by successive courses. It is best known today for its use on some of the older subway systems in the United States , where it is used primarily during rush hour to increase travel speed and long distance travel.
Originally, skip-stop was widely used on streetcars in the United States for a long time. It was introduced at the beginning of the 20th century when the cities grew strongly outward and the distances to be bridged became larger and larger. Skip-stop was only introduced on the subways after the Second World War .
functionality
With skip-stop, the courses (“trains”) on a certain line are divided into two groups and are marked to distinguish them. This is usually done by marking the cars with the letters A and B. The stops along the route in question are marked in the same way, so that it is possible to see which courses stop there and which do not. “A-Halt” (A stops) and “B-Halt” (B stops) alternate; for cocurrent transfers between tensioning assemblies inserted "AB-hold" are used along the route at regular intervals (AB stops) at which keep both groups.
Outside of rush hour, usually only courses are driven that stop everywhere and are accordingly marked with both A and B.
Instead of using letters, skip-stop can also be achieved by operating two different lines overlay.
The same principle can also be found in some elevators. For example, the elevator only has a door on every third floor.
Advantages and disadvantages
The advantages of skip-stop are the increase in travel speed due to a reduced number of intermediate stops and a greater transport capacity due to a denser train sequence. This is particularly advantageous on those routes where there are capacity bottlenecks during rush hour which cannot be remedied by building additional tracks. Not only financial, but sometimes also technical reasons are decisive. For example, the elevated routes of the New York subway always have to make do with only three tracks, because the clear width between the house fronts does not leave room for a fourth track. This means that skip-stop is often the only way to increase transport performance.
One of the disadvantages is that certain destinations cannot be approached at certain times. At the relevant times, it is impossible to get from an A-stop to a B-stop without changing at an intermediate AB stop with a waiting time. Particularly when there is heavy traffic between neighboring city districts, significant traffic problems can arise from passengers changing between the two train groups. The awkward handling also leads to orientation problems among the passengers. Furthermore, the fact that the stops that are not served are partly driven through at full speed, poses considerable dangers for passengers waiting on the platforms.
Examples
- On the Market – Frankford Line in Philadelphia, skip-stop has been used since 1956, especially on the section north of the city center. Trains and stops are marked with the letters A and B.
- With the Chicago 'L' between 1948 and the early 1990s, almost all lines were operated with skip-stop, because the travel times would have been too long due to the high number of stops along the lines in connection with poorly motorized rolling stock in normal operation. With the closure of numerous stations and better vehicles, travel times could be reduced significantly over time, so that skip-stop was abolished in the 1990s.
- An example of skip-stop with different lines is the New York City Subway . On the BMT Jamaica Line , lines J and Z run east of Myrtle Avenue station during rush hour with alternating stops and outside rush hour only line J, which then stops everywhere. A similar configuration existed from 1989 to 2005 on the IRT Broadway – Seventh Avenue Line with lines 1 and 9.
- The Kautenbach – Wiltz railway line in Luxembourg is also skip-stop Monday to Friday: The half-hourly Regional Express trains (RE) from Kautenbach to Wiltz always stop alternately at the two intermediate stations Merkholtz and Paradiso, so that they only run every hour to be served.
Additional information
literature
- Blake, Henry William and Jackson, Walter: Electric Railway Transportation . McGraw-Hill Book Company, New York 1917. (English)
- Gray, George E. and Hoel, Lester A .: Public Transportation . Prentice Hall, Englewood Cliffs, NJ, 1979. ISBN 978-0137391691 . (English)
Web links
- Chicago-L.org: The CTA Takes Over: Resurrection by Modernization (1947–1970) . (English; on the reasons for the introduction of skip-stop at the Chicago 'L')
Individual evidence
- ^ Blake, Henry William and Jackson, Walter: Electric Railway Transportation . McGraw-Hill Book Company, New York 1917. p. 85.
- ↑ Route plan of the Market – Frankford Line ( Memento of the original from May 12, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (Retrieved February 3, 2008 12:05 UTC)
- ^ "The System Contracts as the Fleet Modernizes". In: Chicago-L.org: The CTA Takes Over: Resurrection by Modernization (1947-1970) (Accessed: February 3, 2008, 12:30 UTC)
- ^ The line network plan from 1991 with A and B markings; these have disappeared from the 1995 route network map. (Retrieved: February 3, 2008, 12:25 UTC)
- ↑ see MTA NYC Transit Subway Line Information: J Nassau Street Express ( Memento of the original from January 4, 2007 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. and MTA NYC Transit Subway Line Information: Z Nassau Street Express ( Memento of the original from January 13, 2007 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Metro Briefing | New York: MTA Proposes Dropping No. 9 Train In: The New York Times, January 12, 2005.
