Buses Crossing Borders / Prefecture Border Series 17 / Sakaigawa Bridge

Tokyo-Kanagawa Prefecture Border: Sakaigawa River Part 3
Field survey conducted in July 2024
First edition published 2024/08/07
Data is current as of August 2024 unless otherwise noted.
Drawings and photographs were created or taken by the author unless otherwise noted.

Finally, we have reached a point where the name of the river is the same as the name of the bridge. From this article onwards, the Yokohama Line stations that serve as hubs for bus operations are located on the right bank, or south side, of the Sakaigawa River. The stations are located quite a way up a slope from the riverbank.

Location of Sakaigawa Bridge / Positional relationship with Kobuchi Station

Sakaigawa Bridge is built at a point approximately 2.5 km upstream along the Sakaigawa River from the Morinobashi Bridge mentioned in the previous article. The left bank is Kiso-higashi 2-chome, Machida City, Tokyo / the right bank is Kobuchi 1-chome and 4-chome, Sagamihara City, Kanagawa Prefecture boundary.
The prefecture border also generally follows the Sakaigawa River in this vicinity, although there are subtle differences depending on the map referenced. The river itself does not bend in detail, and even looking at old maps, it does not differ significantly from the current flow. Although river improvement work was carried out, it is estimated that the accompanying changes to the prefecture border were not very large.

The road passing through is a Machida City Road / Sagamihara City Road. The Sagamihara City side is named "Kobuchi Natsutsubaki-dori Street", but there does not seem to be a particular name for the Machida City side. The bridge itself seems to have existed (near this location?) since before the Meiji era. The roads before and after seem to be footpaths (drawn with the symbol for "roads that carts cannot pass through"; in topographic maps of this era, roads with one side drawn as a dashed line correspond to this), but since they extend quite far, they might have been decent roads (investigation incomplete).

Regarding the topography of both banks of the Sakaigawa River, although it is difficult to tell near Machida Station, not only around the Morinobashi Bridge from the previous article, but also around the (other) Tsurumabashi Bridge introduced in the article before that, the Machida City side has a relatively gentle terrain despite the ridge line being close, whereas on the Sagamihara City side, a somewhat steep cliff runs quite close by. In fact, since the JR Yokohama Line moved to the right bank = south bank of the Sakaigawa River, the tracks have been in a cut structure, and Kobuchi Station, which is less than 1 km after crossing the Sakaigawa River, is still in a cut. It is presumed that this structure was adopted because the Yokohama Line was a steam locomotive-hauled train when it opened as the Yokohama Railway in the Meiji era, so it could not handle very steep gradients.
In the first place, Kobuchi Station itself is new, and it is a station that was established in 1988 (Showa 63) after the transition from Japanese National Railways to JR East. The bus road from the station toward the Sakaigawa River area also seems to have been developed around that time, and it descends into a cut. The elevation difference to Sakaigawa Bridge is about a dozen meters.

Bus routes that pass through

Bus routes that cross Sakaigawa Bridge are broadly divided into two.
One is the "Ko02" system Kobuchi Station - Yamazaki Danchi and "Ko03" Kobuchi Station - Fujinodai Danchi, which use Kobuchi Station as the starting and ending point and connect to the residential areas on the Machida City side. Kanagawa Chuo Kotsu's Tama Office is in charge. Both systems follow the same route except for a few stops near the terminal. Together, they operate about twice an hour, but there are days and times when the number of operations is heavily skewed between the two systems. Note that from both terminals, bus routes heading toward Machida Station are operated frequently.

　Another route is the "Machi 09" system Machida Bus Center - Kobuchi Station - National Sagamihara Hospital - Odakyu Sagamihara Station. The route, which previously went via Morinobashi, was changed to go via Kobuchi Station in December 2003 (Heisei 15) and began crossing Sakaigawa Bridge. Later, the "Kobu 09" system, which operates west of Kobuchi Station, was established in July 2016 (Heisei 28) and replaced it. Since December 2019 (Reiwa 1), it has been operating only 6 round trips per day during the daytime on both weekdays and weekends, although the schedules differ. This route is operated by the Sagamihara Office of Kanagawa Chuo Kotsu East.
　The bus stop closest to the bridge on the Sagamihara City side is Kashima Jinja Iriguchi, which is relatively nearby. The bus stops on the Machida City side are located after turning onto Machida Ekimae-dori Street, which runs right near the bridge. The "Kobu 02" and "Kobu 03" systems stop at Sakaigawa Danchi Chuo, located a short distance toward Fuchinobe, while the "Machi 09" system stops at Sakaigawa Danchi Iriguchi, located slightly toward Machida Station. Many bus routes run northwest from Machida Station along this Machida Ekimae-dori Street.

History of Local Governments

　The area on the left bank of the Sakai River in this region was Kiso Village, Tama District, Musashi Province during the Edo period. With the enforcement of the Municipal System in 1889 (Meiji 22), it merged with surrounding villages to become Oaza Kiso, Tadao Village, Minamitama District, Kanagawa Prefecture. After being transferred to Tokyo Prefecture and the implementation of the Tokyo Metropolitan System, it merged with surrounding municipalities in 1958 (Showa 33) and implemented the city system to become Kiso-machi, Machida City, Tokyo. Due to the implementation of residential addressing in 2007 (Heisei 19), the area near the northeast end of the bridge became Kiso-higashi 2-chome, which it remains today.
　The area on the right bank of the Sakai River was part of Fuchinobe Village, Koza District, Sagami Province during the Edo period. With the merger accompanying the enforcement of the Municipal System in 1889 (Meiji 22), it became part of Oaza Fuchinobe, Ono Village, Koza District, Kanagawa Prefecture. In 1941 (Showa 16), it became Sagamihara Town, Koza District, Kanagawa Prefecture through a merger. In 1952 (Showa 27), Oaza Kobuchi was separated from Oaza Fuchinobe. In 1954 (Showa 29), it became Oaza Kobuchi, Sagamihara City, Kanagawa Prefecture upon the implementation of the city system. Residential addressing was implemented in 1991 (Heisei 3), and the area near the southwest end of the bridge became between Kobuchi 1-chome and 4-chome. In 2010 (Heisei 22), with Sagamihara City's transition to a city designated by government ordinance, it became part of Minami Ward, and remains so today.
　Incidentally, when Ono Village was established through a merger in the mid-Meiji period, the village office was located near the current Kobuchi 3-chome. This is because Ono Village was formed by merging several villages along the Kanagawa Orai, which became the prototype for the modern National Route 16, and Kobuchi was located near the middle of it. This location went through later incarnations as a branch office or sub-office of Sagamihara Town/Sagamihara City, and today it serves as the Sagamihara City Minami Ward Ononaka Community Development Center.
　However, because no station was established in this vicinity during the Yokohama Railway to Japanese National Railways era, it did not develop for a long time. Residential development progressed from the late 1960s, and Kobuchi Station was established in 1988 after being transferred to JR East. In 1993, a shopping mall opened along the nearby National Route 16.