67-422: The Sepulveda Transit Corridor is a two-phased planned transit corridor that aims to connect the Los Angeles Basin to the San Fernando Valley through Sepulveda Pass in Los Angeles , California , by supplementing the existing I-405 freeway through the pass. The corridor would partly parallel I-405, and proposed alternatives include heavy rail rapid transit (a subway) or a monorail line connecting
134-539: A Late Miocene depositional age and is divided into four members. The La Vida Member is a micaceous, platy siltstone with subordinate amounts of thin-bedded feldspathic sandstone. The next member is the Soquel, which is a thick bedded to massive micaceous sandstone. Locally abundant siltstone, conglomerate, and intraformational breccia can also be seen in this member. Above the Soquel lies the Yorba Member. This member
201-452: A higher probability of experiencing seismic activity. The region experiences earthquakes that are mostly mild (magnitude ≤2.25). However moderate earthquakes (magnitude 4.9 to 6.4) have been reported. Earthquakes of moderate magnitude are very infrequent. This fault zone is the most notable feature within the basin that is a single strand with local (fault) splays. The fault zone is also marked by low hills, scarps, and ten anticlinal folds in
268-546: A non-marine environment and then transgressed to a deep ocean system. The oldest basement units of this basin are of both sedimentary and igneous origin. The sedimentary unit was metamorphosed as a result of slippage of the Newport–Inglewood fault and is known as the Catalina Schist . The Catalina Schist can be found on the southwestern edge of the basin and is predominantly a chlorite-quartz schist. Closer to
335-492: A refined second set of rail concepts for the corridor, eliminating light rail and rubber-tired metro technology from consideration and narrowing it down to four concepts: In July 2019, Metro released a third refined rail concept after community input. These mainly covered the same routes but with a station added at Santa Monica Boulevard Station in reaction to public feedback. Both costs and ridership projections were higher for these proposals. The feasibility study for both phases
402-585: A regional transit system, was passed in 1980, and a Sepulveda Pass line was in the project map that was part of the proposition's documentation. The Los Angeles County Metropolitan Transportation Authority (Metro) has $ 10 billion in funds available for construction planned to begin in 2026. The plan included in the Measure M transportation funding measure is to build improvements in three stages: additional lanes to be used for express bus service to open by 2028, an 8.8-mile (14.2 km) transit project between
469-545: A right-stepping en echelon pattern. It is located in the southwest portion of the basin and is a strike-slip margin. There are several oil fields that run parallel to this fault. This fault lies on the eastern border of the basin and mergers with the Elsinore Fault in the canyon of the Santa Ana River, one of the upper branches of the fault. This fault is a reverse right-oblique fault. It is most known for
536-598: A separate automated people mover to serve UCLA). In November 2021, the CEQA notice for the project alternatives was released, with an environmental scoping period to begin in February 2022. Rail options were refined to three monorail and three heavy rail alternatives. Monorail options 1 and 2 did not include a station on the UCLA campus and proposed connecting transit options instead. The new alternatives are being considered for
603-522: Is a largely unconsolidated unit and is composed mostly of gravel and floodplain sediments. The sediments that mark the top of the basin can be found in modern streams/rivers and at the base of the foothills. The history of this basin begins with the subduction of Pacific plate underneath the North American plate in the beginning of the Mesozoic. During this subduction event, two smaller plates,
670-444: Is a mid-Miocene fault block that revealed a northwest trending ridge of Paleocene age rocks. This structural feature is important because it revealed many oil traps and orientation of the beds indicate the age of subsidence in this portion of the basin. This particular anticline is the most notable subsurface feature within the basin. Deformation events such as erosion of the uplifted crustal blocks, initiation of various faults, and
737-702: Is a sandy siltstone that is interbedded with a fine-grained sandstone. The Sycamore Canyon Member contains lenses of conglomerate, conglomeratic sandstone, and sandstone. Sandy siltstone and fine-grained sandstones are interbedded with the aforementioned rock types. The Monterey Formation is characterized by abnormally high silica content compared to most clastic rocks. There are also silica-cemented rocks known as porcelanite and porcelanite shale . While this formation has distinguishable beds, there are many shale, sandstone, and mudstone beds that have normal amounts of silica. This sequence of this formation indicates an off-shore marine environment. The Fernando Formation
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#1732772714652804-692: Is bound by the Santa Monica Mountains and Puente, Elysian, and Repetto hills. To the southeast, the basin is bordered by the Santa Ana Mountains and the San Joaquin Hills . The western boundary of the basin is marked by the Continental Borderland and is part of the onshore portion. The California borderland is characterized by northwest trending offshore ridges and basins. The Los Angeles Basin
871-620: Is currently designated as phase 2 of the project is served by Culver CityBus lines 6 and Rapid 6 via Sepulveda Blvd , with the latter only operating weekdays. The lines' northern terminus is the UCLA Gateway Plaza (Westwood/Strathmore). Both lines 6 and Rapid 6 meet the aforementioned Metro 761 in Westwood Village at the Westwood Blvd/Weyburn Ave intersection and at the 761's southern terminus,
938-594: Is currently in the environmental review phase involving the development of an environmental impact report (EIR) under the California Environmental Quality Act (CEQA), and subsequently, an environmental impact statement (EIS) under the National Environmental Policy Act (NEPA). The Draft EIR will evaluate Project alternatives representing a range of rail transit modes, alignments, and station locations for
1005-534: Is essentially phase 1 of the Sepulveda Transit corridor) with bus Route 761, which uses Sepulveda Boulevard to traverse Sepulveda Pass. Its southern terminus is Expo/Sepulveda station on the E Line, and connects to the G Line at its Van Nuys station and Amtrak and Metrolink at their Van Nuys station , before terminating at Sylmar/San Fernando station . It takes about an hour to connect the E and G Lines. Route 233 serves Sepulveda Pass at night. What
1072-732: Is located on the edge of the Pacific plate . The Los Angeles Basin, along with the Santa Barbara Channel , the Ventura Basin , the San Fernando Valley , and the San Gabriel Basin , lies within the greater Southern California region. The majority of the jurisdictional land area of the city of Los Angeles physically lies within this basin. On the north, northeast, and east, the lowland basin
1139-722: Is not due to break ground until 2048. Transit advocates have proposed combining the East San Fernando Valley Light Rail Transit Project and the Sepulveda Transit Corridor Project into a single study to connect Sylmar , Van Nuys , the G Line , Sherman Oaks , UCLA , and the future Westwood/UCLA D Line station. Metro studies declined the LRT merge option and stated HRT would provide faster times and more occupancy on trains. Future extension phases south to
1206-544: Is notable for its great structural relief and complexity in relation to its geologic youth and small size for its prolific oil production. Yerkes et al. identify five major stages of the basin's evolution, which began in the Upper Cretaceous and ended in the Pleistocene . This basin can be classified as an irregular pull-apart basin accompanied by rotational tectonics during the post- early Miocene . Before
1273-417: Is remarkable due to the relatively small size and youth of the basin. The basin currently has about 40 active oil fields that collectively have 4,000 operating wells. In 1904, there were over 1,150 wells in the city of Los Angeles alone. Tight spacing and continued pumping of the wells resulted in most of the wells to dry up. Most recent data indicates that 255 million barrels of oil were produced in 2013. This
1340-521: Is split into two sub-facies known as the Pico and Repetto Members . These members represent a distinct change in the depositional environment and are of Pleistocene age. The Repetto is the older of the two members and is composed of interbedded fine to coarse grained siltstone, mudstone, and sandstone. The Pico Member is mostly made of massive siltstones and sandstones interbedded with minor silty-sandstones. Holocene alluvium and Quaternary sediments
1407-528: Is the Whittier and Newport–Inglewood faults that have dictated the seismic behavior within the basin. The Los Angeles basin is still active tectonically and the region continues to experience earthquakes as a result. Due to the number of faults and fault splays, seismic activity is not concentrated in one particular area. The cities that are overlain by the Newport–Inglewood and Whittier fault zones have
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#17327727146521474-662: The California State Assembly Transportation Committee, implied her support the heavy rail alternatives, citing the monorail alternatives having their stations located in I-405 as well as the need for a station at UCLA. On July 3, 2024, Metro formally eliminated Alternative 2. This follows a request from LASRE for its elimination, along with Metro's independent review and public input in May 2024. Early concepts for phase two from E Line to
1541-423: The E Line , LAX , South Bay , or beyond are also being advocated and proposed. Metro proposed a Centinela Avenue route to LAX or thru Sepulveda Boulevard. No studies have been allocated funds. Phase 1 of the project is part of Metro's Twenty-eight by '28 initiative, which aims to complete its list of expansions in time for the 2028 Summer Olympics . Metro is looking into a public/private partnership to accelerate
1608-638: The G Line in the Valley to the D Line and E Line on the Westside , and the K Line near Los Angeles International Airport . I-405 over Sepulveda Pass between I-10 and US 101 , which the proposed transit line will run parallel to, is the busiest highway corridor in the United States, serving 379,000 vehicles per day. Currently, LA Metro services the Sepulveda Pass corridor (which
1675-605: The LAX Automated People Mover . Rapid 6 is unique in that it has traffic intersection signal priority in the City of Los Angeles, whereas most agencies do not have signal priority outside of their base city. Line 6 completes its run as scheduled in 1 hour 4 minutes with average traffic while the Rapid 6 completes its run with 15 minute headways in 54 minutes as scheduled with average traffic. Total transit time from
1742-551: The Purple Line subway south down Centinela Ave along the same route as the other proposed Centinela Ave concepts (Alt 2). This concept would provide a one-seat ride from the LAX Automated People Mover to Downtown Los Angeles but would require passengers from the San Fernando Valley to transfer at Westwood/UCLA station to travel further south. The second phase of the Sepulveda Transit Corridor Project
1809-437: The (at the time unbuilt but now operational) K Line were released in 2019, with detailed connections to the under-construction LAX Automated People Mover . Metro hopes to complete the feasibility study by 2019 and begin an environmental impact review along with phase one. There are two main modes for phase two of the corridor. Five proposed concepts begin at either Expo/Bundy station or Expo/Sepulveda station , contingent on
1876-670: The Aviation/LAX C Line station to the Van Nuys G Line Station with the aforementioned bus service is about 2 hours plus transfer time. The completion of both phases of this project is estimated to return a total transit time through the whole line of about 45 minutes. The line is a long-established goal in Los Angeles transit planning. Proposition A , which imposed a half-cent sales tax in Los Angeles County to fund
1943-572: The Draft Environmental Impact Report north to south routes from the Valley to E Line were as follows: In April 2021, Metro advanced five routes to the next study stage, including three routes selected as part of Metro's public-private partnership solicitation for the line. The P3 proposals came from Bechtel and BYD Company , with Bechtel submitting the same heavy rail alignment and station proposals as HRT-4, and BYD submitting two monorail proposals that differed from
2010-566: The G Line's Van Nuys Station and the D Line Extension ’s Wilshire/Westwood Station by 2035, and a planned extension to LAX with a 2059 completion date. In April 2017, Metro issued a request for proposal to study alternatives, and several companies sent unsolicited proposals to accelerate the project via public-private partnerships . The project's timeline could be accelerated under the Twenty-eight by '28 initiative. In June 2018, Metro released its initial six alternative rail concepts for
2077-524: The Howard Hughes Center, and Sepulveda Boulevard at Manchester Boulevard. The Sepulveda Boulevard route option would be completed as below-grade heavy rail , while the I-405 option could be completed as either a combination of elevated and below-grade heavy rail or a combination of elevated and below-grade monorail . Metro's July 2019 updated concepts for Phase 2 added a stop along Santa Monica Boulevard per public popular demand. They added
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2144-566: The Los Angeles Metro Rail system. Results of an official public opinion survey conducted by Metro during July and August 2022 to gauge public opinions about the Sepulveda Transit Corridor Project were released in December 2022. After describing details of both rail types were presented to residents, an HRT underground option stood at 71% approval, with respondents citing shorter travel time and fewer surface impacts. The project
2211-633: The Metro E Line's Expo/Sepulveda station . The southern terminus is the Aviation/LAX C line station. As such, the lines indirectly serve LAX , requiring a transfer to a free shuttle bus that serves the station and LAX terminals. They will be rerouted to the LAX Metro Transit center station once it is open, as the station will feature bus bays and direct connections to the LAX terminals by way of
2278-591: The Monterey and Juan de Fuca plates, also began to subduct underneath the North American plate. Around 20Ma, the Monterey plate attached to and followed the motion of the Pacific plate. Later, subduction of the Pacific-Monterey ceased and the plate margin was converted to a transform boundary. The North America/Pacific-Monterey transform boundary began to move north and created crustal extension. This rifting
2345-561: The Newport–Inglewood fault zone, garnet -bearing schists and metagabbros occur. The Santa Monica Slate can be observed in the northwestern block of the basin. The eastern complex is characterized by Santiago Peak Volcanics. This rock unit contains andesitic breccias , flow, agglomerates and tuffs . The Sespe Formation is the first to appear above the great unconformity and is marked by interbedded mudstones, sandstones and pebbly sandstones. This bed sequence indicates an alluvial fan, meandering stream or braided stream origin. Upward from
2412-483: The Sepulveda Transit Corridor Project. Once the draft EIR has been completed and circulated for public comment, Metro staff will recommend a locally preferred alternative (LPA) to the board of directors. After the LPA is identified, the final EIR, draft EIS, and final EIS will be prepared to complete the environmental review process. In October of 2023, Metro released ridership estimates for the six Sepulveda Line options, with
2479-543: The Sespe Formation toward the Vaqueros , the grains become finer and the beds become thinner; indicating a transition to a shallow marine environment. The Vaqueros Formation is marked by two sandstone, siltstone and shale units. There are also characteristic mollusk fossils that indicate the area was dominately shallow marine. The Topanga Group is the next major formation in the stratigraphic sequence and infills
2546-528: The Topanga Group appear to reflect the continuation of a shift in shoreline that can be seen in both the Sespe and Vaqueros formations. Eruptions from one or more of volcanic centers locally and temporarily interrupted sedimentation. The Puente Formation is a deep-marine formation that is characterized by pro-delta sediments and an overlapping fan system. This unit lies above the Topanga Group giving it
2613-487: The Whittier, Brea-Olinda, Sansinena, oil fields. There is an anticline that runs parallel to the Whittier fault that is evidence for compressional deformation during the late Miocene to early Pliocene. Thinning and pinch-out of the Pliocene sandstones are evidence for uplift during this same time period. The Anaheim nose is a subsurface feature that was discovered by geophysical surveys and exploratory drilling in 1930. It
2680-416: The active setting, there are over 9,100 m of strata within the basin. The dynamic setting was also responsible for the heterogeneous deposition of each formation. It is common for rock units of the same depositional event to have different names in different locations within the basin. This may be a result of large variation in clast size as with the upper Pliocene Pico Formation in the northwestern part of
2747-582: The basin and the Upper Fernando Formation in the southwest part of the basin. The Los Angeles Basin contains what is known as the " Great Unconformity " which has been interpreted as a large-scale erosional event in the basement rock unit. This unconformity is used to correlate strata throughout the basin. The record of the Cenozoic activity begins above this unconformity. The stratigraphic record for this basin indicates that it began as
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2814-524: The basin continued to experience sediment deposition through the Pleistocene from flooding and erosional debris from the surrounding mountains and Puente Hills. This infill was responsible for the final retreat of the shoreline from the basin. Deposition in the Holocene is characterized by non marine gravel, sand and silt. This phase also includes the late-stage compressional deformation responsible for
2881-589: The basin lies on the boundary of the Transverse and Peninsular Ranges, this basin experiences both compressional and strike slip tectonics. During the early Pliocene, also identified as the "Basin Disruption" phase, deformation and folding occurred as a result of fault movement and a slight rotation event. While movement along the San Andreas Fault is responsible for the placement of the basin, it
2948-401: The basin. The thickness of these oil sands range from hundreds to thousands of feet. Anticlines and faulted anticlines are the structural features that are also responsible for trapping oil. The first reported oil-producing well was discovered in 1892 on the land that is presently beneath Dodger Stadium . This basin was responsible for half of the states oil production until the (90's?). This
3015-414: The central block. Structurally, there is a synclinal trough. The northeastern block contains fine to coarse grained clastic marine rocks of Cenozoic age. Locally, middle Miocene volcanics can be seen as well as Eocene to Miocene aged non-marine sedimentary rocks. There is also an anticline in the northeastern block. Homogeneous evolution of this basin did not occur due to dynamic tectonic activity. Despite
3082-400: The corridor. All of the proposals provided connections between the G Line (at Sepulveda , Van Nuys , or both) and the E Line (at Expo/Sepulveda or Expo/Bundy ), as well as to the D Line Extension , currently under construction, and to the East San Fernando Valley Light Rail Transit Project , currently being planned. The proposals fell into four categories: In January 2019, Metro released
3149-571: The development of the submarine channel led to the anticline's formation. Fold initiation began in the late-Miocene to early Pliocene period of deformation. There are many other anticlines within the basin and isopach data suggests that the formation of these folds occurred mostly during the Pliocene. The La Brea Tar Pits are pools of stagnant asphaltum that have been found on the basin's surface. These "pools" are important because hundreds of thousands of late Pleistocene bones and plants have been found. These pits allowed scientists to better understand
3216-408: The ecosystem at that particular point in the geologic past. Accumulations of oil and gas occur almost wholly within strata of the younger sequence and in areas that are within or adjacent to the coastal belt. The Puente formation has proved to be the most notable reservoir for petroleum in the basin. The primary reason for the high abundance of oil is because the oil sands are well saturated within
3283-411: The end of this phase, the shoreline began to retreat and deposition continued. After the deposition of the pre-Turonian units, there was a large emergence and erosion that can be observed as a major unconformity at the base of the middle Miocene units. Emergence did not occur at the same rate or in all sections of the basin. During this time, the basin was covered by a marine embayment. Rivers sourced in
3350-505: The fifth concept, extending the east/west Purple Line Extension terminus south towards LAX, creating a one-seat HRT trip from LAX to Downtown Los Angeles along Centinela Avenue. All north-to-south routes from the E Line to LAX are: The following table shows all potential metro stations and the alternatives for which they apply: Alternative 5's concept for the Westside-LAX phase of the Sepulveda Transit Corridor Project would extend
3417-495: The formation of the basin, the area that encompasses the Los Angeles basin began above ground. A rapid transgression and regression of the shoreline moved the area to a shallow marine environment. Tectonic instability coupled with volcanic activity in rapidly subsiding areas during the Middle Miocene set the stage for the modern basin. The basin formed in a submarine environment and was later brought back above sea level when
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#17327727146523484-468: The formation of the hydrocarbon traps. Four major faults are present in the region and divide the basin in the central, northwest, southwest, and northeast structural blocks. These blocks not only denote their geographic location, but they indicate the strata present and major structural features. The southwestern block was uplifted prior to the middle Miocene and is composed mostly of marine strata and contains two major anticlines. This block also contains
3551-417: The highland areas (to the north and east) moved down the submarine slopes and infilled the basin floor. Subsidence and sedimentation most likely began in the southern portion basin. Subsidence and Deposition occurred simultaneously, without interruption, until the late Pliocene. Until the rate of deposition gradually overtook the rate of subsidence, and the sea level began to fall. Towards the end of this phase,
3618-463: The highlands brought large amounts of detritus to the northeastern edge of the basin. During this period, the Topanga formation was also being deposited. The present form and structural relief of the basin was largely established during this phase of accelerated subsidence and deposition which occurred during the late Miocene and continued through the early Pleistocene. Clastic sedimentary rocks from
3685-734: The identification of costs and cost reductions. The study also called for more information to be gathered on the impact of the Santa Monica Fault near Santa Monica Boulevard. The Metro Board then commenced the NEPA and CEQA scoping process. Two engineering firms were chosen to prepare pre-development materials for the two potential modes. Monorail proposals were developed by BYD LA SkyRail Express, while heavy rail (HRT) work proposals were prepared by Bechtel . By December 2021, six alternatives had been prepared for further consideration: three heavy rail and three monorail (one of which included
3752-444: The margins of the basin began to rise above sea level. During the early Pleistocene, deposition began to outpace subsidence in the depressed parts of the basin and the shoreline began to move southward. This phase also had movement along the Newport–Inglewood fault zone that resulted in the initiation of the modern basin. This movement caused the southwestern block to be uplifted relative to the central basin block. The central part of
3819-702: The opening. Los Angeles Basin The Los Angeles Basin is a sedimentary basin located in Southern California , in a region known as the Peninsular Ranges . The basin is also connected to an anomalous group of east–west trending chains of mountains collectively known as the Transverse Ranges . The present basin is a coastal lowland area, whose floor is marked by elongate low ridges and groups of hills that
3886-415: The original MRT-1 alternative studied by Metro. The following table shows all potential metro stations and the alternatives for which they apply: Future southern terminus station of the East San Fernando Valley Light Rail Transit Project . Three Maintenance and Storage Facility (MSF) options are being proposed. In March 2021, Metro awarded contracts to two firms to develop two alternatives to advance
3953-481: The project. A plan for conventional heavy rail (HRT) is being developed by Bechtel . The rival design is a monorail as planned by BYD LA SkyRail Express (LASRE). A scoping process carried out by Metro from November 2021 to February 2022 showed a majority of the public favoring heavy rail over monorail, 93% to 7% respectively. Heavy rail alternatives were cited by comments as having better transfer options to other lines, faster travel times, and more familiarity with
4020-491: The rate of subsidence slowed. There is much discussion in the literature about the geologic time boundaries when each basin forming event took place. While exact ages may not be clear, Yerkes et al. (1965) provided a general timeline to categorize the sequence of depositional events in the LA Basin's evolution and they are as follows: During pre- Turonian , metamorphosed sedimentary and volcanic rocks are present that serve as
4087-492: The results greatly favoring the heavy rail option. Estimates showed that the heavy rail alternatives (4-6) not only had higher ridership than the monorail alternatives (1-3) by between 21,000 to 57,000 daily riders, but the heavy rail alternatives also were 8-14 minutes faster and had quicker connections to other lines in the LA Metro system, such as the D and E lines. In addition, state assemblywoman Laura Friedman , chair of
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#17327727146524154-619: The steeply-dipping Palos Verdes Hills fault zone. The middle Miocene volcanics can be seen locally within the southwest block. The northwestern block consists of clastic marine sediments of Late Cretaceous to Pleistocene age. Middle Miocene volcanics are also present. This block has a broad anticline that is truncated by the Santa Monica fault zone. The central block contains both marine and non-marine clastic rock units interbedded with volcanic rocks that are late Cretaceous to Pliocene in age. Pliocene and Quaternary strata are most visible within
4221-656: The terminus of the first phase of the project. All routes terminate at the LAX/Metro Transit Center station , which is currently under construction as part of the Crenshaw/LAX Transit Corridor Project . This terminus station will offer transfers to the K Line and LAX Automated People Mover. Concepts include routing south along Sepulveda Boulevard, Overland Avenue, Centinela Avenue, and I-405 , with possible intermediate stops at Venice Boulevard, Culver City Transit Center,
4288-417: The topography on older rocks. It is a mixed sedimentary and volcanic unit whose base is an erosional unconformity. The unit consists of 3 parts: First is a basal marine conglomeratic sandstone, followed by a dominantly basaltic middle layer of multiple submarine lava flows and tuffs. The youngest part of this unit is a sedimentary breccia, conglomerate, sandstone, and a siltstone . The earliest deposits of
4355-400: The two major basement rock units for the LA Basin. Large-scale movement along the Newport–Inglewood zone juxtaposed the two bedrock units along the east and west margins. During this phase, the basin was above sea level. The hallmarks of this phase were successive shoreline transgression and regression cycles. Deposition of older marine and non-marine sediments began to fill the basin. Towards
4422-488: Was accompanied with the rotation of the western Transverse Ranges. This rotation is responsible for the placement and northwest–southeast orientation of the LA Basin. Early in the Miocene, before deposition of the Topanga, high heat flow and transtension caused the extension of the basin. As the crust thinned, the basin began to subside from isostatic pressure as a result of large amounts of sediment deposition. Because
4489-525: Was completed and presented in November 2019, with no significant refinement from the July 2019 presentation. The study said that additional research was needed on whether the project would need to relocate or maneuver around a nine-foot wide DWP water pipe called the "Sepulveda Feeder." Additional studies were also called for on general station locations, tunnel design configuration, rider transfer patterns, and
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