1. Atami Station: Where Japan's First Platform Doors Were Installed
When you think of platform doors, you might picture crowded commuter train stations. However, the first installation in Japan was at Atami Station on the Tokaido Shinkansen in January 1974. [4] Atami Station could not have a passing track for trains that did not stop there, due to land constraints. As a result, high-speed trains passed very close to the edge of the platform. As the number of trains and passengers increased, it became difficult to restrict people from entering the platform area, so platform doors were installed in 1974. [4]
The first platform doors were built to match the door positions of the Shinkansen trains of that era (the 0 series). Later, when the train models changed, they were replaced with doors for the N700 and 700 series in 2011 and 2012. [4] Platform doors are equipment that must align perfectly with the train's doors. This requirement to "match the door positions" would later become a major barrier when expanding to other stations.
2. Platform Doors Protect People From Falls and Contact With Trains
Platform doors are equipment designed to reduce falls from platforms and contact with trains. A report from the Ministry of Land, Infrastructure, Transport and Tourism states that if accidents decrease, train delays associated with them also decrease, and that these doors help increase users' sense of security. [5]
Looking at the numbers, falls from platforms by all users peaked in fiscal year 2014 and decreased to 2,887 cases in fiscal year 2019. Among these, falls by people with visual impairments peaked in fiscal year 2015 and were 61 cases in fiscal year 2019, accounting for only 2 to 3 percent. [5] Most people who fell were users without visual impairments. Platform doors are often thought of as equipment for people with visual impairments, but the materials define them as safety equipment for all users. [5]
However, the report does not state that this decrease in numbers is solely due to platform doors. Other measures, such as tactile paving blocks, were also being implemented at the same time. [5] If we understand that platform doors are being developed as safety equipment for everyone, not just as welfare equipment for specific groups, why weren't they installed at all stations immediately, even though their necessity for safety is understood?
3. Different Train Door Positions Made Installation Difficult
Trains arriving at a station are not all the same type. On lines where multiple railway companies run trains onto each other's tracks, trains with different numbers of cars and different door positions operate. Even on a single company's line, there are examples where express and local trains have different door positions. The Ministry of Land, Infrastructure, Transport and Tourism report states that this is a hurdle for installing platform doors. [5]
The doors of the platform screen must align with the doors of all trains. It is like receiving various sizes of luggage at a fixed counter position. But in reality, it is not that the counter is in a bad position, but that the luggage arrives at different places each time. Construction time is also limited. Work cannot be done while trains are running, so it must be done in the short time after the last train and before the first train's inspection begins. [5]
Misaligned doors and lack of construction time are two problems, and money issues add to them. Like Atami Station in 1974, an environment where only limited train models (like the Shinkansen) arrive was actually the example where conditions were most aligned.
4. Installation Cost and Weight of Platform Doors
The other barrier is cost. The report states that the initial cost per station (for two tracks, up and down) is several hundred million to over one billion yen. This includes reinforcement work for the platform. After installation, maintenance costs are about 3 million to 20 million yen per year per track. [5]
Weight is also a problem. Traditional platform doors are designed to withstand a self-weight of about 450 to 500 kg per opening. For platforms on embankments, reinforcing them to support this weight is said to be particularly expensive. [5]
The path to increasing platform doors was not a debate about whether safety is important, but a technical challenge of how to create models that are lighter, cheaper, and can adapt to differences in door positions.
5. Lighter Platform Door Models That Fit Different Train Door Positions
One turning point was the field trials announced by the Ministry of Land, Infrastructure, Transport and Tourism in March 2013. These trials tested new models that could address issues of door position differences and costs, including sliding pocket-door types, lifting rope types, and lifting bar types, supported by subsidies. The announcement clarified that this was not a decision to adopt them. [6]
The advantage of lifting types is that they do not require "pockets" to store the doors. A pocket is a place to store open doors. Without pockets, the width of the opening can be widened, making it easier to accommodate trains with different door positions. [3] Regarding weight, lightweight models are said to be about half the weight of traditional models, requiring less reinforcement work and allowing transport by truck, which keeps costs down. [5] [3] On March 28, 2015, a lifting-type platform door was trial-installed at Haijima Station on the JR East Hachiko Line. [3]
A report in July 2019 stated that new models, such as lightweight platform doors, were beginning to be put into practical use to reduce installation and reinforcement costs. It called for planning and development by track number. [7] With the creation of lighter models with wider openings, the number of stations where they could be installed increased.
6. How the Number of Stations With Platform Doors Grew
Let's look at the numbers. However, it is important not to mix up years and fiscal years, or station counts and track counts. A "track count" refers to the platform face for each track. Traditional platform doors were at 318 stations as of March 2007 and 593 stations as of September 2014, an increase of about 1.9 times. [3] After that, according to the Cabinet Office White Paper, there were 686 stations in 2016 and 943 stations at the end of fiscal year 2020. [2] According to Ministry of Land, Infrastructure, Transport and Tourism data, there were 1,190 stations (2,830 tracks) at the end of fiscal year 2024. [1]
At stations with 100,000 or more daily users, there were 353 tracks as of July 2019. [7] By the end of fiscal year 2024, this had risen to 621 tracks, an increase of about 1.8 times. [1] The national target is 3,000 tracks overall and 800 tracks at stations with over 100,000 users for fiscal years 2021 to 2025. [1]
This comparison places numbers from different sources side by side. Because the scope of data collection may differ slightly, please read this as a rough overview.
7. Longer Stop Times: The Trade-off of Installing Platform Doors
Installing platform doors adds time to open and close the doors. As a result, stop times extend. In busy periods like morning rush hours, where train intervals are tight, delays are said to be more likely to propagate to subsequent trains. As a real example, on the former Osaka Municipal Subway Sennichimae Line, chronic timetable disruptions occurred during platform door installation. Therefore, the timetable was revised to extend stop times and allow more time for boarding and alighting. In exchange, the total travel time for the entire line increased. [8] Similarly, on the Midosuji Line (2 stations) and the Yokohama Municipal Subway Blue Line, it is reported that stop times were given more margin. [8]
Platform doors can add time to a train's stop. Railway companies create timetables while looking at both sides of this balance. The examples introduced here are based on news reports and are not meant to imply that the same thing happens on every line. Increasing safety creates a burden elsewhere. The balance between safety and delays appears in different forms depending on the line.
8. How to Observe Door Position Misalignment at a Station With Platform Doors
At a station with platform doors, try observing these three things. Do not approach the edge of the platform; observe from inside the yellow line. First, when the train stops, check if the train's doors and the platform door's doors align. Next, check if the platform door's opening is wider than the train's door. Finally, when opening and closing, check if there is a protrusion like a pocket on the side of the door, or if it is a type that moves up and down.
Comparing with platform doors at other stations or lines reveals differences in shape. However, you cannot determine the model or reason for installation by appearance alone. If you are curious, check the materials below. To verify numbers and systems, the Ministry of Land, Infrastructure, Transport and Tourism's page on installation status [1] and the report on installation [5] are good starting points.