# Japan National Route 423

National Route 423 (国道423号, Kokudō Yonhyaku ni-jusangō) is a national highway of Japan connecting Kita-ku, Osaka and Kameoka, Kyoto in the Kansai region of Japan.

## Route description

National Route 423 has a total length of 50.6 kilometers (31.4 mi).

### Minō Toll Road

The Minō Toll Road is a 7.2-kilometer-long (4.5 mi) two-lane toll road in Minoh, Osaka that connects the Shin-Meishin Expressway to the southern limits of the city via a tunnel under Mount Minō. It is a part of Route 423 that is tolled and maintained by the Osaka Prefectural Road Corporation.

### Shinmidō-suji

The Shinmidō-suji is a 7.2-kilometer-long (4.5 mi) controlled-access highway that runs from the northern terminus of the Midōsuji in Kita-ku to the southern terminus of the Minō Toll Road in Minoh. From Kita-ku to Toyonaka, the median of the highway is utilized by the Midōsuji Line and Kita-Osaka Kyuko Railway.

## History

Much of what is now National Route 423 was part of the Settan-kaido, a road linking Ikeda in what was Settsu Province and Kameoka in what was then Tanba Province.
In 1964, the portion of the route between Kita-ku and Osaka Prefecture Route 9, known as the Shinmidō-suji, was built alongside the extended Midōsuji Line to accommodate automobile traffic from Shin-Ōsaka Station into central Osaka. Later in the decade, Shinmidō-suji was extended north again along with the Midōsuji Line to Suita were the venue for the Expo '70 was. National Route 423 was established in 1982 along the Shinmidō-suji, the planned Minō Toll Road, and the older Settan-kaido.
The Minō Toll Road section was opened to traffic on 30 May 2007 between Osaka Route 9 and the northern terminus at the Ikeda–Minoh route of National Route 423, completing the route. On 10 December 2017 the highway was connected to the Shin-Meishin Expressway at the northern terminus of the Ikeda–Minoh route and the toll road.

## List of major junctions

| Prefecture | Location | km | mi | Exit | Name | Destinations | Notes |
| Osaka | Kita-ku, Osaka | 0.0 | 0.0 | — | Umeshin-minami | National Route 25 south (Midōsuji) | Southern terminus; traffic can only travel southbound on Midōsuji |
| Osaka | Kita-ku, Osaka | 0.2 | 0.12 | — | Umeshin-higashi | National Route 1 (Sonezaki-dori) | Partial interchange; southern end of controlled-access highway segment |
| Osaka | Yodo River | 2.313.06 | 1.441.90 | Shin-Yodogawa Great Bridge | Shin-Yodogawa Great Bridge | Shin-Yodogawa Great Bridge |
| Osaka | Yodogawa-ku, Osaka | 3.4 | 2.1 | — | Nishinakajima | Osaka Prefecture Route 16 (Yodogawa Route) | Northbound exit, southbound entrance |
| Osaka | Yodogawa-ku, Osaka | 4.2 | 2.6 | — | Shin-Ōsaka | Shin-Osaka Station access road | |
| Osaka | Suita | 7.0 | 4.3 | — | Esaka | National Route 479 | |
| Osaka | Suita | 11.0 | 6.8 | — | Momoyamadai | Osaka Prefecture Route 35 (Toyonaka-Settsu Route) | |
| Osaka | Toyonaka | 12.6 | 7.8 | — | Senri | Osaka Prefecture Route 2– to Chūgoku Expressway | |
| Osaka | Minoh | 15.3 | 9.5 | — | Minō | National Route 171 – Kyoto, Kobe | Northern end of controlled-access highway segment |
| Osaka | Minoh | 16.2 | 10.1 | — | Hakushima | Osaka Prefecture Route 9 | Southern terminus of the Minō Toll Road; northern terminus of Shinmidō-suji; southbound entrance, northbound exit |
| Osaka | Minoh | 23.4 | 14.5 | 13 | Minō-Todoromi | National Route 423 south (Ikeda-Minoh route) / Shin-Meishin Expressway – Kyoto, Tsuyama, Okayama, Ikeda, Toyono | Northern terminus of the Minō Toll Road |
| Osaka | Toyono | 21.0 | 13.0 | — | Kanaishibashi | Osaka Prefecture Route 4 | |
| Osaka | Toyono | 22.7 | 14.1 | — | Kishiroguchi | Osaka Prefecture Route 110 south | |
| Osaka | Toyono | 23.2 | 14.4 | — | Kishiroguchi | Osaka Prefecture Route 109 east | |
| Osaka | Toyono | 24.4 | 15.2 | — | Myokenguchi | Osaka Prefecture Route 605 west | |
| Kyoto | Kameoka | 27.9 | 17.3 | — | Yunohara | Kyoto Prefecture Route 733 east | |
| Kyoto | Kameoka | 30.5 | 19.0 | — | Waroji | Kyoto Prefecture Route 732 west | |
| Kyoto | Kameoka | 36.3 | 22.6 | — | Sogabe | Kyoto Prefecture Route 407 | |
| Kyoto | Kameoka | 38.0 | 23.6 | 13 | Kameoka | National Route 372 west / Kyoto Jūkan Expressway | Southern end of Route 372 concurrency; interchange |
| Kyoto | Kameoka | 38.1 | 23.7 | — | Kazanokuchi | Kyoto Prefecture Route 406 west | |
| Kyoto | Kameoka | 39.1 | 24.3 | — | Kazuka | National Route 9 (San'indō) / Kyoto Prefecture Route 403 east | Northern terminus; northern end of Route 372 concurrency |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi Concurrency terminus Incomplete access ||||||||

### Ikeda–Minoh route

The entire toll road is in Osaka Prefecture.
| Location | km | mi | Exit | Name | Destinations | Notes |
| Ikeda | 0.0 | 0.0 | — | Kibechō | National Route 173 | Southern terminus |
| Ikeda | 0.3 | 0.19 | 11-14 | Ikeda-Kibe Daiichi | Hanshin Expressway Ikeda Route | Northbound entrance, southbound exit |
| Minoh | 6.2 | 3.9 | 13 | Minō-Todoromi | National Route 423 / Shin-Meishin Expressway – Kyoto, Tsuyama, Okayama, Ikeda, Toyono | Northern terminus of the Ikeda-Minoh route |
| Through to National Route 423 (main route) |||||||
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi Incomplete access |||||||