# Japan National Route 465

National Route 465 (国道465号, Kokudō Yonhyaku roku-jūgogō) is a national highway located entirely within Chiba Prefecture, Japan. It connects the cities of Mobara and Futtsu, spanning the Bōsō Peninsula in an east–west routing. The highway has a total length of 111.0 kilometers (69.0 mi).

## Route description

National Route 465 connects the cities of Mobara and Futtsu, spanning Chiba Prefecture's Bōsō Peninsula in an east–west routing. The highway has a total length of 111.0 kilometers (69.0 mi), though the first 25.0 kilometers (15.5 mi) of the highway that runs concurrently with National Route 128, is not signed as National Route 465. The highway's eastern terminus lies at a junction with National Route 409 in Mobara, where it begins its concurrency with National Route 128. The two highways pass through the municipalities of Chōsei and Ichinomiya heading south towards the city of Isumi along the eastern coast of the peninsula.
In Isumi the highways diverge, with National Route 128 continuing south along the coast towards the southern tip of the peninsula and National Route 465 heading west towards its interior, paralleling the Isumi Line. Crossing into the mountainous town of Ōtaki, the highway meets National Route 297 just to the west of the town's central district. The two highways share a brief concurrency running south through the relatively dense area, after which National Route 465 continues west, paralleling the Isumi Line to the railway's terminus at Kazusa-Nakano Station.
Crossing into the city of Kimitsu, the highway continues winding its way west through the peninsula's mountainous interior. Near Kazusa-Kameyama Station the highway curves to the northwest and meets National Route 410 shortly after. The highways share another concurrency descending from the mountains, traveling though the narrow Yomachisaku Daiichi Tunnel, and then curving towards the southwest. The two routes diverge at the foot of Mount Kano. National Route 465 passes into the city of Futtsu directly to the south of the mountain. Just to the east of central Futtsu, the highway meets National Route 127, they share yet another concurrency traveling north together through central Futtsu towards the Tateyama Expressway. The aforementioned highways travel alongside each other for a brief period with Futtsu-chūō interchange linking them before the highways all separate within the vicinity of Sanukimachi Station. National Route 465 travels directly to that train station, paralleling the Uchibō Line to the highway's western terminus at a junction with National Route 16 on Cape Futtsu.

## History

In 1902, the Yomachisaku Daiichi Tunnel (四町作第一隧道, Yomachisaku Daiichi Zuidō) was completed using only hand tools along what would become National Route 465 in the city of Kimitsu. The tunnel is the second oldest tunnel that is designated as a part of a national highway in Japan.
National Route 465 was established by the Cabinet of Japan in 1993. A re-aligning and widening project along the highway in the city of Kimitsu was completed on 31 March 2015. The project resolved problems created by several repetitive tight curves. The straightened roadway decreased the length of National Route 465 by 200 meters (660 ft). On 23 December 2015, a 20-meter-long (66 ft) section of the Yomachisaku Daiichi Tunnel's shotcrete lining collapsed following a re-application of the supportive lining a month prior to the collapse. The tunnel lining was repaired by the following day.

## Major intersections

The route lies entirely within Chiba Prefecture.
| Location | km | mi | Destinations | Notes |
| Mobara | 0.0 | 0.0 | National Route 409 west – Kisarazu Chiba Prefecture Route 27 south – Katsuura, Ōtaki | Eastern terminus; eastern end of National Route 409 concurrency, highway continues south as Chiba Prefecture Route 27 |
| Mobara | 0.2 | 0.12 | National Route 128 north / National Route 409 east – Chiba, Tōgane | Western end of National Route 409 concurrency, eastern end of National Route 128 concurrency |
| Chōsei | 4.8 | 3.0 | Chiba Prefecture Route 85 south / Chiba Prefecture Route 293 west – Mutsuzawa | Eastern end of Chiba Prefecture Route 293 concurrency |
| Chōsei | 6.0 | 3.7 | Chiba Prefecture Route 293 north – Seibu Industrial Park | Western end of Chiba Prefecture Route 293 concurrency |
| Chōsei | 6.9 | 4.3 | Chiba Prefecture Route 227 north – Yatsumi Station | |
| Ichinomiya | 9.2 | 5.7 | Chiba Prefecture Route 123 – Ichinomiya Beach, Shirako | |
| Ichinomiya | 9.8 | 6.1 | Chiba Prefecture Route 148 west | No direct access to Chiba Prefecture Route 148, one-way street |
| Ichinomiya | 9.9 | 6.2 | Chiba Prefecture Route 228 east – Kazusa-Ichinomiya Station | |
| Ichinomiya | 13.3 | 8.3 | Chiba Prefecture Route 274 west – Matsumaru | |
| Ichinomiya | 14.2 | 8.8 | Chiba Prefecture Route 152 south – Misaki | |
| Ichinomiya | 15.7 | 9.8 | Chiba Prefecture Route 30 north – to Kujūkuri Toll Road [ja], Kujūkuri | |
| Isumi | 18.4 | 11.4 | Chiba Prefecture Route 229 west – Taitō Station | |
| Isumi | 20.7 | 12.9 | Chiba Prefecture Route 152 north – Misaki | |
| Isumi | 24.3 | 15.1 | National Route 465 west (Fukahori Bypass) – Ōtaki | |
| Isumi | 25.2 | 15.7 | National Route 128 south – Katsuura, Onjuku | Western end of National Route 128 concurrency |
| Isumi | 26.9 | 16.7 | National Route 465 east (Fukahori Bypass) – to National Route 128 | |
| Isumi | 31.3 | 19.4 | Chiba Prefecture Route 176 – Yamada, Onjuku | |
| Isumi | 34.1 | 21.2 | Chiba Prefecture Route 154 east – Misaki | |
| Isumi | 35.0 | 21.7 | Chiba Prefecture Route 85 north – Mobara | |
| Isumi | 37.1 | 23.1 | Chiba Prefecture Route 82 south – Kominato, Katsuura | |
| Isumi | 37.6 | 23.4 | Chiba Prefecture Route 151 north – Mutsuzawa | |
| Ōtaki | 40.5 | 25.2 | National Route 297 north (Ōtaki-Kaidō) – to Ken-Ō Expressway, Ichihara, Chiba Chiba Prefecture Route 172 west – Central Ōtaki | Eastern end of National Route 297 concurrency |
| Ōtaki | 42.0 | 26.1 | Chiba Prefecture Route 231 north – Central Ōtaki, Ōtaki Prefectural Forest | |
| Ōtaki | 42.4 | 26.3 | National Route 297 south (Ōtaki-Kaidō) – Kamogawa, Katsuura | Western end of National Route 297 concurrency |
| Ōtaki | 51.1 | 31.8 | Chiba Prefecture Route 177 south – Kominato, Katsuura | |
| Ōtaki | 51.6 | 32.1 | Chiba Prefecture Route 32 west – Kururi | |
| Ōtaki | 54.8 | 34.1 | Chiba Prefecture Route 81 north – Chiba, Yōrō Keikoku Chiba Prefecture Route 178 south – Okitsu, Mamenbara | Eastern end of Chiba Prefecture Route 81 concurrency |
| Kimitsu | 59.0 | 36.7 | Chiba Prefecture Route 81 south – Kamogawa, Kiyosumi | Western end of Chiba Prefecture Route 81 concurrency |
| Kimitsu | 67.4 | 41.9 | Chiba Prefecture Route 24 south (Kururi Kaidō) – Kamogawa | Eastern end of Chiba Prefecture Route 24 concurrency |
| Kimitsu | 68.0 | 42.3 | National Route 410 north / Chiba Prefecture Route 24 north (Kururi Kaidō) | Eastern end of National Route 410 concurrency, western end of Chiba Prefecture Route 24 concurrency |
| Kimitsu | 76.6 | 47.6 | National Route 410 south – Tateyama, Seiwa Prefectural Forest | Western end of National Route 410 concurrency |
| Kimitsu | 81.7 | 50.8 | Chiba Prefecture Route 92 / Chiba Prefecture Route 93 east (Bōsō Skyline) – to Tokyo Bay Aqua-Line, Kamogawa | Eastern end of Chiba Prefecture Route 93 concurrency |
| Kimitsu | 82.5 | 51.3 | Chiba Prefecture Route 93 west – Mount Kano | Western end of Chiba Prefecture Route 93 concurrency |
| Futtsu | 92.7 | 57.6 | Chiba Prefecture Route 182 south (Momiji Road) – Hota | |
| Futtsu | 95.6 | 59.4 | Chiba Prefecture Route 93 east – Mount Kano | Eastern end of Chiba Prefecture Route 93 concurrency |
| Futtsu | 96.1 | 59.7 | Chiba Prefecture Route 93 west – to National Route 127, Kazusaminato | Western end of Chiba Prefecture Route 93 concurrency |
| Futtsu | 98.2 | 61.0 | National Route 127 south (Uchibō Nagisa Line) – Tateyama, Hamakanaya | Eastern end of National Route 127 concurrency |
| Futtsu | 99.9 | 62.1 | Tateyama Expressway – to Tokyo Bay Aqua-Line, Chiba, Kawasaki, Tateyama | Futtsu-chūō Interchange (E14 exit 19) |
| Futtsu | 101.2 | 62.9 | National Route 127 north (Uchibō Nagisa Line) – Chiba, Kisarazu Chiba Prefecture Route 163 east – to Bōsō Skyline, Mount Kano | Western end of National Route 127 concurrency, eastern end of Chiba Prefecture Route 163 concurrency |
| Futtsu | 102.0 | 63.4 | Chiba Prefecture Route 163 ends Chiba Prefecture Route 256 south – Shinmaiko Beach | Western end of Chiba Prefecture Route 163 concurrency |
| Futtsu | 105.8 | 65.7 | National Route 465 north (Uchibō Bypass) – Kimitsu | |
| Futtsu | 110.2 | 68.5 | Chiba Prefecture Route 255 west – Cape Futtsu | |
| Futtsu | 111.0 | 69.0 | National Route 16 – Cape Futtsu, Kisarazu Chiba Prefecture Route 90 – to Tateyama Expressway, Chiba, Kisarazu | Western terminus; highway continues north as Chiba Prefecture Route 90 |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi Concurrency terminus Incomplete access Route transition |||||