Tama Monorail Extension: When It Opens and Tachikawa’s Future Guide

When does the Tama Monorail extension open? Seven stations, 7.0 km and a mid-2030s target, a 16 km plan to Machida, and Tachikawa at the middle of it all.

日本語で読む（Japanese version）

At its northern end, the Tama Monorail simply stops in mid-air.

Just past the northern edge of Kamikitadai Station, the grey guideway beam breaks off. Beyond it there is nothing but the sky over Shin-Ome-kaido Avenue. It looks less like a dead end than like a sentence someone started and then thought better of finishing.

Out past that broken-off end in the air, seven stations are now drawn on the plans. On 9 May 2025, Japan’s Minister of Land, Infrastructure, Transport and Tourism granted a licence to extend the line from Kamikitadai to the area around Hakonegasaki Station. Length: 7.0 kilometres. Stations: seven. Project cost: about 129 billion yen. Target opening: the mid-2030s. And at the end of the extension lies a city that is the only one of the 26 cities of Tokyo with no railway station at all.

Once I started looking into it, I found myself holding a question. Why does it take so long to draw a single line joining the north and south of Tama? And when that line does grow, what will Tachikawa (立川), sitting at the middle of this road in the sky, turn into?

(A word of orientation first. Tokyo is not only the dense 23 wards most visitors know. Its long western half, the Tama area, is a country of commuter cities, hills and rivers, and Tachikawa is one of its main hubs. The Tama Monorail, run by Tokyo Tama Intercity Monorail Co., Ltd., is the line that crosses Tama from north to south, with Tachikawa partway along it.)

When will the Tama Monorail extension open? Past Kamikitadai, into the sky over Shin-Ome-kaido

Let me give the answer first. The extension from Kamikitadai to Hakonegasaki is under way, with an opening targeted for the mid-2030s. The materials the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) released on 9 May 2025 set it out in a short list: seven stations to be built, 7.0 kilometres of double track, opening in the mid-2030s, a project cost of about 129 billion yen (tax included). The branches towards Machida and Hachioji are still at the “concept” stage.

The more detailed numbers are in the Tokyo Metropolitan Government’s announcement. On 27 November 2025 Tokyo obtained approval for the urban planning project from MLIT and started work. The section runs from Kamikitadai 1-chome in Higashiyamato City to Oaza Hakonegasaki Aza Sayama in Mizuho Town, Nishitama District. Its length is 7,055 metres. The project period runs from fiscal Reiwa 7 to Reiwa 16, which is to say from fiscal 2025 to fiscal 2034. (Reiwa is the current imperial era, which began in 2019; Japanese official documents count years by era.) Machida City’s own explanation says the Hakonegasaki extension is “being built with the aim of opening in fiscal 2034”. The share of the cost Tokyo carries is 90.4 billion yen; the rest falls to the company.

This division of labour is one of the curious things about a monorail. According to the national government’s materials, the structures that form the skeleton, the pillars, the beams and the station buildings, are built by Tokyo as the “infrastructure part”, while what is needed for running and managing the line, the trains, the power lines, the ticket machines and so on, is built by Tama Toshi Monorail, the operating company, as the “non-infrastructure part”. Machida City puts it more bluntly: the guideway beams, pillars and stations are treated as part of the road, so they are built by whoever manages the road. In the eyes of the law, a monorail beam is a kind of road. Look up at a grey girder floating in the sky and be told “that is a road”, and it takes a moment to sink in.

The road-ness shows even in the names. In the town-planning documents, the dedicated way for the extension is called “Tachikawa Urban Planning Road 9-6-1, Tama Nambokusen” and “Fussa Urban Planning Road 9-6-1, Tama Nambokusen”. Nambokusen means “north-south line”. So: the Tama North-South Line. It is a name with no poetry in it at all, and yet no name could be more honest. A road for joining the south and north of Tama, and it claims to mean nothing else.

The track will run down the middle of Shin-Ome-kaido Avenue. Tokyo’s explanatory slides show the monorail passing along the centre of the avenue, with stations lined up beside the drawings one sheet at a time, provisionally named No. 2, No. 3 and so on. According to Tokyo’s materials, the platforms at the six intermediate stations (provisionally No. 1 to No. 6) will be about 66 metres long and about 8.5 metres wide. The terminus, provisionally Station No. 7, will be placed next to Hakonegasaki Station on the JR Hachiko Line. The trains will be the same straddle type as now, riding on top of the beam, and a four-car train carries about 400 people.

There is one small note in the national materials. The widening of Shin-Ome-kaido Avenue, the space the line will occupy, has already begun. Before you can build a road in the sky, you have to widen the road on the ground. Work on the extension starts not with putting up beams but with fattening up the avenue.

So who, at the far end of that fattened avenue, is waiting for the monorail more than anyone?

To the only city in Tokyo without a station

Musashimurayama City has no railway station.

The city’s public transport plan says so in a single line: at present, there are no railway stations in the city. A booklet published for a research presentation by one of the city’s schools has a sentence with a little more feeling in it. Our city, it says, is known as “the only city or ward in Tokyo with no railway station”. The extension of the Tama Toshi Monorail was a policy that could be called the long-cherished wish of many citizens. The same booklet calls the town-planning decision of March 2025 that brought stations to the city “the dawn of Year One of the Tama Toshi Monorail extension”, and writes that five stations are planned within the city. Of the seven new stations, five will gather in this one city.

“Long-cherished wish” does not seem to be an exaggeration. Norimono News, a specialist transport news site, reports that railway plans for this area came up again and again over the years and then vanished. According to the article, in 1915 a company called the Murayama Light Railway received a licence to build a line from Hakonegasaki through Murayama and Higashimurayama to Kichijoji. The licence later passed to the Kawagoe Railway and became the skeleton of the Murayama Line between Takadanobaba and Higashimurayama, today’s Seibu Shinjuku Line. In 1930 the line was extended from Higashimurayama to Murayama-Chosuichi-mae, by the reservoir, but the section beyond it to Hakonegasaki never opened. The line that was meant to head for Musashimurayama ended up, short of its goal, as part of somebody else’s railway. The article calls this “a railway on hold for a hundred years”. Telling people who have already waited a hundred years to please wait another ten takes a certain courage on the part of whoever does the telling.

There was a small discovery at the other end of the line too. In the list of shareholders on the Tama Toshi Monorail company profile, the name of Mizuho Town appears. Its stake is 0.65%, the same as Tachikawa City’s. A town that does not yet have a single metre of track already owns shares in the company. On opening day it will greet its nearest station as a shareholder. It is a patient investment, but then everyone involved with this line is patient.

The city’s transport plan does not only write optimism. Next to it, it lays out that bus use fell during the COVID-19 pandemic and has still not returned to its earlier level, and that with driver shortages and rising fuel costs there is a risk that “public transport running as a matter of course” may no longer be something people can take for granted. That is exactly why the plan makes the monorail the trunk line between cities and then rebuilds the network of buses and small-scale transport that feeds the stations. A station opening is written not as the finish line but as the chance to reweave the town’s transport from scratch. Today the city is served by ordinary route buses, by a city loop bus called the “MM Shuttle”, and by “Mura-Taku”, a shared taxi for residents who have registered to use it. A town without a station has managed, with buses and shared taxis, to stand in for a railway.

And the seventh station, the terminus at Hakonegasaki? On the map it looks like a straightforward end of the line. But it turned out to hide an unexpected complication.

The last station sits under the base’s sky

The script for the slides Tokyo used at its briefings on the town-planning proposal is surprisingly good reading if you take your time with it. The extended track heads west along the centre of Shin-Ome-kaido Avenue, and on the way, around the Mizuho Town Hall Entrance intersection, a set of points will be installed so that trains can cross between the up and down tracks. As far as the Hakonegasaki underpass the line keeps to the middle of the avenue, but beyond that it swings north to avoid existing structures, and runs along the east side of Fussa Road 3-4-10 to reach the area by Hakonegasaki Station.

For the terminus, provisional Station No. 7, the script lists four headaches. The road in front of JR Hakonegasaki Station is only 20 metres wide, not enough to fit a monorail station. Two intersections follow one after the other at the entrance to the station plaza. The plaza’s present functions have to be kept. And on top of that, the airspace restrictions of Yokota Air Base apply.

The end of the road in the sky is bound by the needs of a different sky. Tachikawa was once an airfield town. Now a monorail stretching north from Tachikawa runs, at its far end, straight into an airfield’s airspace again. The skies over Tama look roomy, but then and now they are more crowded than they seem. (Yokota Air Base is a US military airfield in western Tama, and around an airfield the height of anything you build is restricted.) In the end Tokyo decided to widen the road on the east side of the station front and place the monorail station there. Fussa Road 3-4-10 will be widened from its planned 20 metres to 35.5 metres.

Around the intermediate stations, too, the road grows fatter. Near provisional Station No. 6, Shin-Ome-kaido Avenue, planned at 30 metres wide, will be widened to 37 metres to make room for a connecting walkway to the station. Construction proceeds in this order: in each section where the land has been secured in one piece, the water mains and sewers are moved, traffic is shifted to the outer lanes, a work yard is set up in the centre of the road, and the monorail is built there. After the monorail is finished, traffic is moved back towards the centre, a shared utility tunnel is laid, and the utility poles disappear. While a road is being threaded through the sky, the overhead wires on the ground vanish underground. The benefits of the extension cannot be measured by passenger numbers alone.

So what steps did this long-cherished wish climb to get this far? Lay out the timeline and you see just how patient everyone has been.

From recommendation to approval: a long timeline

The story of the extension begins with a recommendation from a national advisory council. In April 2016, Report No. 198 of the Council for Transport Policy, “On the future of urban railways in the Tokyo area”, positioned the extension of the Tama Toshi Monorail in three directions: Kamikitadai to Hakonegasaki, Tama-Center to Hachioji, and Tama-Center to Machida. The significance of each is described in exactly the same words: improving access between the main districts of the Tama area. What differs is the column for issues. For Hakonegasaki, it says that roads that could serve as the space for the line are being built, and that concrete coordination towards making it a project should go ahead. That one sentence pushed Hakonegasaki to the front of the queue.

Here is the timeline from there, picked out of the documents of Tokyo, the company and the national government.

In January 2020, Tokyo put money in its budget towards making the extension a project. In October 2022, briefings were held on the draft town plan, and the survey plan for the environmental impact assessment was submitted. The draft environmental impact statement followed in November 2023, and the response to comments on it in May 2024. On 23 July 2024, the company applied for a licence under the Tramways Act. On 6 February 2025, Tokyo submitted the final environmental impact statement to the governor. It covered eight items: noise and vibration, soil contamination, shading, radio interference, landscape, historic sites and cultural properties, places for contact with nature, and waste. In March 2025 the town plan was decided; on 9 May the national government granted the licence; on 27 November Tokyo started the project.

Then, on 22 May 2026, the company received from the Minister of Land, Infrastructure, Transport and Tourism what is called “approval for the first divided stage of track construction”. It covers the parts that are mainly civil engineering, the pillars, the guideway beams, the station buildings and so on; the “second stage”, mainly electrical, still has to be applied for separately, according to news reports.

The company’s announcement quoted the article of the Tramways Act on which this procedure rests, just as it stands in the statute book: Article 5. The tramway operator shall apply for approval of the execution of works within the period designated by the Minister of Land, Infrastructure, Transport and Tourism. In the original it is written in the stiff classical Japanese of early-20th-century law, with katakana in place of the usual hiragana, the kind of prose a modern reader has to slow down for. A vehicle that will run through the sky of 2026 and beyond is moving forward through procedures phrased in a voice from a century ago. The vehicle of the future runs on very old words.

From the council’s recommendation to approval of the works: exactly ten years. Or, counting from Musashimurayama’s side, 111 years since the 1915 licence. Depending on which ruler you use, this extension is either “at long last” or “already”.

The Tama Monorail extension in numbers

• 7,055 — metres. The length of the extension section for which Tokyo received project approval. That is 55 metres longer than the “7.0 km” in the national materials. Even the odd metres have their reasons.
• About 129 billion — yen. The total project cost, infrastructure and non-infrastructure parts combined. Tokyo’s share is 90.4 billion. Divide by 7.0 km and it comes to about 18.4 billion yen per kilometre (my own calculation).
• 7 — the number of new stations the extension creates. Five of them are planned for Musashimurayama, a city that has no station today.
• About 66 — metres. The length of the new platforms. Just enough for a four-car train carrying about 400 people.
• 53,033,000 — total passenger journeys in fiscal 2025. Up 4.8% on the year before, and a record. The road in the sky is getting crowded even before it grows.
• 0.65% — the share of the company held by Mizuho Town. The town at the end of the line became a shareholder before the track arrived.

Traveller’s detour quiz

In the town-planning documents, the dedicated monorail way on the extension section has an official name. Which is it?

1. Tama Nambokusen (Tama North-South Line) (B) Shin-Ome Monorail Street (C) Sayama Sky Avenue

The answer comes near the end of this article.

The towns at the far end of the extension are waiting for their stations. So what is happening at the other end of the road in the sky, beyond Tama-Center in the south? There, a 16-kilometre stretch is still waiting for its line to be drawn.