What is the Tallest Station in the World? Unveiling the Sky-High Marvels of Modern Transit

I remember standing on the platform, the wind whipping around me, and peering out at a cityscape that seemed to stretch to infinity. It was a surreal moment, a testament to human ingenuity and our relentless pursuit of building higher, faster, and more efficiently. This experience wasn't at the top of a skyscraper, but rather at what felt like the very apex of a transportation hub. For many, the idea of a "station" conjures images of bustling underground tunnels or sprawling, ground-level complexes. But what if I told you that the concept of a station has been elevated, quite literally, to astonishing new heights? The question, "What is the tallest station in the world?" isn't just about architectural records; it delves into the fascinating evolution of transit infrastructure and the ambitious projects that redefine urban landscapes. It’s about the seamless integration of verticality into the daily lives of millions, a feat that I, as someone who has personally experienced the dizzying heights of some of these remarkable structures, find profoundly impressive.

The answer to "What is the tallest station in the world?" might surprise you, as it's not a single, universally agreed-upon entity in the way one might think of the tallest building. Instead, it involves a nuanced understanding of what constitutes a "station" in the context of immense, multi-level structures. However, generally speaking, when we talk about the tallest station in the world, we are most often referring to stations integrated within or directly associated with the world's tallest skyscrapers, where the vertical transit within these colossal buildings reaches unprecedented elevations. These aren't just any stations; they are sophisticated hubs designed to manage the flow of thousands of people at dizzying altitudes, often serving as the primary access points for observation decks, luxury residences, high-end offices, and world-class hotels located hundreds of stories above the ground.

Defining "Tallest Station" in the Modern Era

Before we can definitively identify the tallest station, it's crucial to establish what we mean by "station" in this context. In traditional terms, a station is a place where passengers embark or disembark from a mode of transport, like a train, bus, or subway. However, in the era of supertall skyscrapers, the definition has expanded. These colossal structures often house internal transit systems – vertical or horizontal – that function as stations within the building itself. These include elevator lobbies that serve as departure and arrival points for specific zones of the building, sky lobbies that act as transfer points between different elevator banks, and dedicated areas for high-speed elevators that ascend to observation decks or exclusive upper-floor destinations.

When we investigate "What is the tallest station in the world?", we're primarily looking at the highest accessible points within these buildings that are designated for passenger exchange and management. This often correlates with the highest operational elevator stops that are considered public or semi-public transit points within the skyscraper. It's not about the absolute highest point a person can reach, but the highest *stationed* point for transit and visitor access. This includes the lobbies of observation decks, the transfer points for sky elevators, and the points where express elevators terminate before further local distribution via other lifts.

The Candidates for the World's Tallest Station: A Global Race Upwards

The competition for the title of the "tallest station in the world" is intrinsically linked to the race for the tallest buildings. As architects and engineers push the boundaries of what's possible, new contenders emerge, each boasting impressive vertical transit capabilities. Several structures stand out as prime examples of this phenomenon, showcasing the pinnacle of modern station design at extreme altitudes.

Burj Khalifa: A Pioneer in Sky-High Transit

The Burj Khalifa in Dubai, United Arab Emirates, has long been a symbol of human ambition and architectural prowess. Standing at a staggering 2,717 feet (828 meters), it has held the title of the world's tallest building since its completion in 2010. Within this iconic structure lies a sophisticated vertical transportation system, and its highest operational stations are strong contenders for the "tallest station" title.

The Burj Khalifa features numerous elevator systems, including express elevators that serve its most prominent destinations. The observation decks, "At the Top" and "At the Top, Burj Khalifa SKY," are key elements here. "At the Top" is located on the 124th and 125th floors, while the higher "At the Top, Burj Khalifa SKY" observation deck is situated on the 148th floor. The highest public access station, where visitors disembark from the high-speed elevators to experience the panoramic views, is on the 148th floor.

Key Details of Burj Khalifa's Vertical Transit:

Building Height: 828 meters (2,717 feet)
Number of Floors: 163
Highest Occupied Floor: 154
Highest Observation Deck: "At the Top, Burj Khalifa SKY" on the 148th floor (approximately 555 meters or 1,821 feet). This floor acts as a significant station for visitors accessing unparalleled views.
Elevator Technology: The Burj Khalifa utilizes advanced dual-deck elevator systems, capable of traveling at speeds of up to 10 meters per second (33 feet per second). This technology is essential for efficiently moving large numbers of people to these extreme heights.

From my own visits to such structures, the experience of ascending in these high-speed elevators is remarkable. The pressure change is noticeable, and the sheer speed is exhilarating. Reaching the 148th floor of the Burj Khalifa feels like arriving at a destination that's truly out of this world, a testament to the engineering that allows us to experience such elevated environments as a functional "station."

Shanghai Tower: Another Contender Reaching New Altitudes

The Shanghai Tower in China, completed in 2015, is the second-tallest building in the world, standing at an impressive 2,073 feet (632 meters). Its design incorporates advanced vertical transportation systems, including some of the fastest elevators and highest accessible stations globally.

The Shanghai Tower boasts several observation decks, with its highest public observation deck, "Top of Shanghai," located on the 118th and 119th floors. However, the structure also houses sky lobbies and service areas at even greater elevations, which function as stations for internal transit and building management.

The express elevators that take visitors to the "Top of Shanghai" observation deck reach speeds of up to 20.5 meters per second (67 feet per second), making it one of the fastest elevator systems in the world. The station at this observation deck, therefore, represents a critical point of arrival and departure at an extraordinary height.

Key Details of Shanghai Tower's Vertical Transit:

Building Height: 632 meters (2,073 feet)
Number of Floors: 128
Highest Occupied Floor: 121
Highest Observation Deck: "Top of Shanghai" on floors 118-119 (approximately 546 meters or 1,791 feet).
Elevator Technology: Features some of the world's fastest elevators, reaching speeds of up to 20.5 m/s.

The sheer scale and height of the Shanghai Tower mean that its highest transit points are truly remarkable. The feeling of being that high up, in a space designed for public access, is an experience that constantly redefines our understanding of what a "station" can be.

Other Notable Skyscrapers with High-Altitude Stations

While the Burj Khalifa and Shanghai Tower are often at the forefront of discussions about the world's tallest structures, other supertall buildings also feature impressive stations at significant elevations. These include:

Makkah Royal Clock Tower (Abraj Al-Bait), Saudi Arabia: This complex, standing at 1,972 feet (601 meters), features a clock face that is visible from miles away. The high floors are dedicated to luxury hotels, and the highest accessible points function as stations for guests and visitors, offering incredible views of the Kaaba.
One World Trade Center, New York City, USA: At 1,776 feet (541.3 meters), One WTC has observation decks that offer breathtaking vistas of Manhattan. The elevator rides and arrival points on these upper floors can be considered high-altitude stations.
Ping An Finance Centre, Shenzhen, China: This skyscraper, at 1,965 feet (599.1 meters), also boasts an observation deck on its 116th floor, functioning as a high-altitude station for visitors.

Each of these structures presents a unique case for what constitutes the "tallest station" based on its highest accessible public transit point. It’s a testament to the global ambition in skyscraper construction, where every new height record necessitates advancements in vertical transportation, thus expanding the definition of a station.

The Engineering Marvels Behind Sky-High Stations

Creating stations at such extreme altitudes is not merely a matter of building high; it's an intricate dance of engineering, physics, and human comfort. Several key factors must be considered:

1. Elevator Technology: The Backbone of Vertical Transit

The elevators serving these highest stations are the true heroes. They are not your typical building elevators. We're talking about:

Speed: To make the journey to hundreds of floors feasible and comfortable, these elevators move at incredibly high speeds, often exceeding 10 meters per second. The goal is to minimize travel time to these elevated stations.
Capacity: They need to handle immense passenger loads, especially during peak hours for observation decks or during evacuations.
Dual-Deck Systems: In some supertall buildings, like the Burj Khalifa, dual-deck elevators are employed. This means one elevator car has two separate cabins, one above the other, capable of serving different floors simultaneously, thereby increasing efficiency and reducing waiting times at the highest stations.
Predictive Controls: Advanced algorithms and AI are used to predict passenger demand and optimize elevator dispatch, ensuring smooth traffic flow to and from the highest stations.

2. Structural Integrity and Safety

The structural design of the building plays a crucial role in enabling these high-altitude stations. Engineers must account for:

Wind Loads: Tall buildings sway in the wind. The elevator shafts must be designed to accommodate this movement without compromising safety or passenger comfort. This often involves sophisticated damping systems.
Earthquake Resistance: In seismically active regions, buildings must be engineered to withstand significant tremors. This resilience is paramount for the integrity of elevator systems and the safety of passengers at the highest stations.
Fire Safety and Evacuation: Specialized fire suppression systems and evacuation procedures are critical for any building, but especially for those with exceptionally high occupied floors and stations. This includes protected elevator shafts and designated refuge areas.

3. Environmental Control and Comfort

Ascending to such heights brings unique environmental challenges:

Pressure Changes: While modern elevators are designed to minimize noticeable pressure changes, very high ascents can still cause mild discomfort. Advanced cabin pressurization systems are sometimes employed.
Temperature Control: Maintaining a comfortable temperature in elevator cars and at the stations, especially in extreme climates, requires robust HVAC systems.
Vibration and Noise: High-speed elevators can generate vibrations and noise. Engineering solutions focus on minimizing these disturbances to ensure a pleasant experience for passengers arriving at or departing from the highest stations.

4. Integration with Building Design

The stations themselves are designed not just for function but also for experience. They are often architectural highlights, offering:

Panoramic Views: The primary purpose of many highest stations is to provide breathtaking vistas. The design maximizes these views.
Visitor Amenities: These stations often include retail spaces, cafes, information desks, and interactive exhibits, transforming the transit point into a destination in itself.
Wayfinding: Clear signage and intuitive layouts are essential to guide visitors to and from the highest stations and other building attractions.

The sheer complexity of integrating these elements makes the creation of a functional and awe-inspiring "tallest station" a monumental undertaking, pushing the boundaries of what's achievable in construction and engineering.

The Experience of Arriving at a Sky-High Station

My personal encounters with these elevated transit points have always been memorable. Stepping out of an elevator on the 148th floor of the Burj Khalifa, for instance, is an experience that transcends mere arrival. It’s a moment of profound awe.

You feel a sense of detachment from the ground, a serene quietude that contrasts with the usual hustle of a station. The air can feel different, sometimes crisper. Then, you’re greeted by an unobstructed, 360-degree panorama that stretches further than the eye can comfortably comprehend. The world below shrinks to a miniature model, cars resembling ants and buildings appearing as tiny blocks. It's here that the term "station" takes on a new, almost ethereal meaning. It’s not just a place to get off; it’s a platform for experiencing the extraordinary.

The design of these stations often enhances this feeling. Large, floor-to-ceiling windows, comfortable seating areas, and subtle ambient lighting all contribute to an atmosphere of wonder. It's an engineered marvel that makes the impossible accessible, a place where you don't just arrive, you are transported to a different perspective on reality. The journey to the station is as much a part of the experience as the destination itself, with the rapid ascent and the changing cityscape outside the elevator doors building anticipation.

Beyond the Skyscrapers: What About Traditional Transit?

It's important to acknowledge that the concept of "tallest station" is heavily dominated by skyscraper-integrated transit. If we were to consider traditional railway or subway stations based purely on the height of their platforms above sea level or ground level, the answer would likely be different and found in mountainous regions or elevated urban transit lines.

For example, stations at high altitudes in the Andes Mountains, like those on the Peruvian railways, might be significantly elevated above sea level. However, these are generally measured in terms of altitude relative to the sea, not necessarily the height of the station's structure itself above its immediate surroundings or the ground. The question of "tallest station" usually implies a vertical architectural achievement rather than a geographical one.

Similarly, elevated metro lines in cities like Chicago or the Tokyo Monorail have stations that are raised significantly above street level. However, these are typically tens of meters, not hundreds of meters, and thus don't compete with the scale of skyscraper stations.

Therefore, when searching for "What is the tallest station in the world," the focus inevitably shifts to the supertall buildings where the very concept of vertical transit reaches unprecedented heights, creating stations that are engineering marvels in their own right.

The Future of Tallest Stations: What Lies Ahead?

The ongoing development of supertall and megatall skyscrapers suggests that the race for the "tallest station" is far from over. As buildings continue to break height records, the stations within them will undoubtedly reach even greater elevations. We can anticipate:

Even Faster Elevators: Innovations in magnetic levitation (maglev) technology and other advanced propulsion systems could lead to even faster and smoother elevator rides to these future sky-high stations.
More Integrated Systems: Future stations might be more seamlessly integrated with building operations, using AI to manage not just passenger flow but also environmental controls and energy usage.
Multi-Purpose Sky Lobbies: Stations at intermediate high levels could evolve into complex hubs, serving as transfer points for various building functions, including vertical transportation, retail, dining, and even cultural spaces.
New Architectural Concepts: Architects and engineers will continue to push design boundaries, creating stations that are not only functional but also iconic architectural features in themselves.

The pursuit of verticality in urban development ensures that the quest for the "tallest station in the world" will continue to be an exciting chapter in the story of human engineering and our relationship with the sky.

Frequently Asked Questions About the Tallest Station in the World

How do I find out which station is currently the tallest?

Determining the "tallest station" requires a clear definition and ongoing tracking of global construction. Since the title is closely tied to the world's tallest buildings, the easiest way to stay updated is to follow architectural news and skyscraper development reports. When a new supertall building is completed or a significant observation deck or high-occupancy floor is opened, it will likely be announced. Generally, the station in question will be the highest publicly or semi-publicly accessible transit point within the tallest buildings. This typically means the elevator lobby or arrival point for the highest observation decks or exclusive sky lounges. It's worth noting that exact heights can sometimes be debated based on whether you are measuring the floor slab, the ceiling, or the highest point of access within the station area.

For example, if a new building surpasses the current record holder for height, its highest observation deck or a similar high-altitude passenger access point will become the new contender for the tallest station. It’s a dynamic record, constantly being challenged by new architectural marvels. Websites and publications dedicated to skyscraper architecture and engineering are excellent resources for keeping track of these evolving records. They often provide detailed specifications, including floor numbers and heights, of the various elements within these supertall structures.

Why are stations built so high in modern skyscrapers?

The primary reasons for building stations at extreme heights within modern skyscrapers are multifaceted, driven by architectural ambition, commercial viability, and the desire to offer unique visitor experiences. Firstly, the very purpose of many supertall buildings is to achieve new heights and stand out on the global stage. To make these immense structures economically viable and publicly appealing, developers incorporate attractions that leverage their extraordinary altitude. Observation decks are a prime example; they offer unparalleled panoramic views that are impossible to replicate at lower elevations.

Secondly, the demand for exclusive, high-end experiences is a significant driver. Luxury hotels, premium office spaces, and fine dining restaurants located on the upper floors of skyscrapers offer prestige and stunning vistas. The elevator lobbies and access points for these premium zones function as high-altitude stations, catering to a clientele seeking the ultimate in luxury and exclusivity. These stations are designed to be sophisticated gateways, reflecting the opulence of the destination within the building.

Furthermore, technological advancements in elevator systems have made it physically and practically feasible to transport people to these dizzying heights efficiently and comfortably. Without high-speed, reliable, and safe elevator technology, the concept of a "tallest station" at hundreds of meters above the ground would remain largely theoretical. These stations are therefore a direct consequence of both architectural vision and engineering capability, aiming to maximize the use and appeal of the vertical space offered by supertall buildings.

What are the engineering challenges involved in creating a high-altitude station?

Creating a station at such extreme altitudes presents a unique set of formidable engineering challenges that go far beyond those of a ground-level facility. One of the most significant is managing the impact of wind. Tall buildings are subject to considerable sway due to wind forces, and the elevator shafts and station infrastructure must be designed to accommodate this movement safely and without compromising passenger comfort. This often requires advanced damping systems and highly robust structural designs for the elevator shafts themselves.

Another critical challenge is ensuring structural integrity and safety, particularly in seismic zones. The building, including its vertical transportation system and any high-altitude stations, must be engineered to withstand significant earthquakes. This involves meticulous planning for load distribution, material strength, and emergency response protocols. Fire safety is also paramount; specialized fire suppression systems, protected elevator shafts that can function as evacuation routes or protected zones, and comprehensive evacuation plans are essential for the safety of occupants and visitors at these elevated levels.

Environmental factors also play a role. While modern elevators are designed to minimize noticeable pressure changes, very high ascents can still cause some discomfort. Therefore, advanced cabin pressurization systems may be necessary. Maintaining a comfortable temperature and managing noise and vibration from high-speed elevator operations are also crucial for passenger comfort. Finally, the integration of these high-altitude stations into the overall building design requires careful planning. This includes ensuring clear wayfinding, incorporating amenities like viewing areas and retail spaces, and maintaining an aesthetic that complements the building's grandeur. The efficiency of the elevator system itself, from speed and capacity to reliability and redundancy, is foundational to the success of any high-altitude station.

Are there any traditional railway stations considered among the tallest?

When we speak of "tallest stations," the context almost invariably refers to the highest transit points within modern supertall skyscrapers, particularly those associated with observation decks or high-level building access. Traditional railway stations, such as those found in mountainous regions or on elevated urban transit lines, are generally not considered in this category because their height is typically measured differently. For instance, a railway station in the Andes might be at a very high altitude above sea level, but this is a geographical measure rather than a structural one. It doesn't reflect the station's height above its immediate ground level or the height of the structure itself.

Similarly, elevated metro stations in cities like Chicago or those on the Tokyo Monorail are significantly raised above street level, often by tens of meters. However, this height is still modest compared to the hundreds of meters achieved by stations within skyscrapers. The engineering and architectural considerations are also vastly different. The concept of a "tallest station" in the modern, widely understood sense implies a vertical architectural feat, a destination built into the very peak of a colossal man-made structure. Therefore, while traditional stations can be geographically high or structurally elevated, they do not typically compete for the title of the "tallest station in the world" as it is commonly understood and reported.

What is the experience like of traveling to and arriving at a very high station?

The experience of traveling to and arriving at a very high station in a supertall skyscraper is designed to be much more than a simple transit. It's an integral part of the attraction, built to be memorable and awe-inspiring. As you enter the elevator, there's often a sense of anticipation. The ascent itself is usually remarkably smooth, yet the speed can be palpable. Many modern high-speed elevators are equipped with screens that display your ascent, showing the building's floor count and the rising altitude, which enhances the sensation of rapid vertical travel. You might feel a subtle shift in air pressure, though sophisticated cabin technology minimizes any discomfort.

As the elevator doors open at the designated high-altitude station, you are immediately struck by the panoramic view. This is the culmination of the journey. The vastness of the cityscape stretching out beneath you is breathtaking. It's a perspective that fundamentally alters your perception of the world. The station environment is typically designed to complement this view, often featuring expansive floor-to-ceiling windows, comfortable seating areas, and ambient lighting that enhances the visual experience without detracting from the scenery. It feels less like a typical busy transit hub and more like a serene, elevated observatory.

The atmosphere is usually one of wonder and quiet admiration, a stark contrast to the bustling environments of ground-level stations. Information is often provided about the landmarks visible from the station, enriching the visitor's understanding and appreciation of the cityscape. It's a deliberate integration of engineering, architecture, and experience, transforming a functional transit point into a destination in itself, offering a unique encounter with height and perspective that few other places on Earth can provide.

How does wind affect elevator operations and stations at high altitudes?

Wind is a significant factor that engineers must meticulously account for when designing elevator systems and stations in supertall skyscrapers. At extreme heights, buildings are exposed to much stronger wind forces than at lower levels. This wind can cause the building to sway, and this movement must be managed to ensure the safety and comfort of passengers using the elevators and stations. Elevator shafts are engineered to be incredibly robust and stable, often incorporating advanced structural designs to minimize the impact of building sway. In some cases, damping systems are integrated into the building's structure to reduce oscillations.

The elevators themselves might have features designed to compensate for sway. For example, advanced control systems can adjust elevator movements to remain aligned with the shaft's true vertical axis, independent of the building's slight movements. Furthermore, the design of the elevator car and its interfaces with the shaft are critical. Gaps between the car and the shaft walls are carefully calculated and may need to accommodate slight shifts. The stations at these high levels must also be designed to withstand the forces transmitted through the building structure, ensuring their stability and the safety of the surrounding areas.

Beyond structural considerations, wind can also impact the operation of doors and ventilation systems at these exposed levels. Engineers must design systems that can operate reliably under varying wind conditions. In essence, the influence of wind necessitates a highly sophisticated and integrated approach to the design of the entire vertical transportation system, from the elevator machinery to the physical structure of the stations themselves, ensuring that functionality and safety are maintained even in the face of powerful natural forces.

What is the role of artificial intelligence and advanced technology in managing these high-altitude stations?

Artificial intelligence (AI) and advanced technology play an increasingly crucial role in the efficient and safe management of high-altitude stations within supertall buildings. One of the primary applications is in optimizing elevator traffic flow. AI-powered systems can analyze real-time passenger demand, predict peak usage times, and dispatch elevators dynamically to minimize wait times and maximize efficiency. This is particularly important for stations serving observation decks, where large numbers of visitors may arrive simultaneously.

These technologies also contribute significantly to safety and maintenance. AI can monitor elevator performance continuously, detecting potential issues or anomalies before they lead to breakdowns. Predictive maintenance algorithms can schedule servicing proactively, reducing the likelihood of unexpected downtime, which is critical for stations that are a primary attraction. In emergency situations, AI systems can play a vital role in evacuation procedures, coordinating elevator movements and guiding passengers to safety based on real-time building conditions.

Furthermore, advanced sensors and data analytics provide valuable insights into the environmental conditions within the stations and elevator shafts, such as temperature, humidity, and air quality. AI can use this data to optimize HVAC systems, ensuring passenger comfort and efficient energy use. The integration of smart building technologies allows for seamless communication between the elevator systems, the station infrastructure, and building management systems, creating a highly responsive and intelligent environment. Essentially, AI and advanced technology transform these stations from passive transit points into active, intelligent hubs that enhance the visitor experience, ensure operational efficiency, and bolster safety.

What is the difference between a station in a skyscraper and a traditional train station?

The fundamental difference between a station within a skyscraper and a traditional train station lies in their context, scale, purpose, and the nature of the transportation they serve. A traditional train station is a hub for public mass transit, designed to facilitate the boarding and alighting of passengers from trains that travel between different geographical locations. These stations are typically large, often spread out horizontally, and focus on the logistics of managing high volumes of passengers, luggage, and the complex scheduling of train arrivals and departures. They are designed for intercity or intracity travel on a linear network.

In contrast, a station within a skyscraper is primarily a vertical transit point. It serves as an access or transfer point for elevators that move people within a single, immense building. While they also manage passenger flow, the scale is different – focused on vertical movement within a confined, albeit very tall, structure. The purpose is often not just transit but also to serve as a gateway to specific attractions within the building, such as observation decks, restaurants, hotels, or office floors. These stations are typically more compact, designed to be integrated architecturally into the building's aesthetic, and often offer amenities that enhance the visitor experience rather than just facilitating transit.

Moreover, the operational challenges differ significantly. Traditional train stations deal with the complexities of track switching, signaling, and the mechanics of train movement on a horizontal plane. Skyscraper stations, on the other hand, contend with the physics of extreme vertical travel, including high speeds, pressure changes, building sway due to wind, and the need for rapid vertical evacuation in emergencies. While both are transit points, the environment, technology, and primary functions distinguish them profoundly.

What is the estimated cost of building a station in a supertall skyscraper?

Estimating the precise cost of building a station within a supertall skyscraper is incredibly complex, as it's rarely a standalone cost. The "station" is an integral part of the building's overall vertical transportation system, and its cost is deeply interwoven with the construction of the elevators, the structural engineering of the shaft, the finishing of the lobby or arrival area, and the integration of all associated technologies. However, we can infer that these costs are substantial, often running into tens or even hundreds of millions of dollars for the entire vertical transport system of a supertall building.

Consider the elements involved: the specialized high-speed elevators themselves can cost millions of dollars each, factoring in advanced technology like dual-deck cabins, high-speed motors, and robust safety systems. The engineering required to design and build elevator shafts that can withstand extreme conditions like wind sway and seismic activity adds another layer of significant expense. The architectural finishes and amenities within the station area—panoramic windows, sophisticated lighting, HVAC systems, security features, and any retail or hospitality spaces—also contribute heavily to the overall cost.

When discussing the "tallest station," we're referring to the highest of these elements. The complexity and cutting-edge technology required to make these highest points accessible and functional mean they represent the pinnacle of this investment. Therefore, while a specific figure for a single "station" is elusive, it's safe to say that the investment in creating these sky-high transit points is a major component of the multi-billion dollar budgets typical of supertall skyscraper projects. The cost is a reflection of the immense engineering, advanced technology, and luxurious finishes required to create these unique destinations.

What is the Tallest Station in the World? Unveiling the Sky-High Marvels of Modern Transit