LONDON, UK — May 18, 2026 — Japan’s extensive highway network is renowned for its efficiency, but a growing number of drivers are encountering a perplexing—and potentially dangerous—design flaw known as “中途半端JCT” (nakatoban JCT), or “halfway junctions.” These problematic intersections, where highways intersect without full interchanges, force motorists onto unexpected routes or leave them stranded without direct access to intended destinations.
While urban highways like Tokyo’s Metropolitan Expressway often feature these junctions, rural areas are now seeing increased attention after several high-profile incidents. Road authorities and transportation experts warn that the issue—often overlooked in planning—poses safety risks and creates navigation headaches for both locals and tourists. The problem has become so pronounced that some junctions are now being retrofitted with full interchanges at significant cost.
World Today Journal examined official transportation records, government advisories, and recent engineering projects to uncover how these junctions work, why they exist, and what drivers should do when encountering them.
What Is a “Halfway Junction” (中途半端JCT)?
A halfway junction occurs when two highways intersect without a complete set of ramps connecting all possible directions. Instead of allowing seamless transitions—such as from Highway A to Highway B in any direction—drivers are forced onto local roads or must backtrack, creating confusion and potential safety hazards.
For example, at the 鶴岡JCT (Tsuruoka Junction) in Yamagata Prefecture, where the 山形自動車道 (Yamagata Expressway) meets the 日本海東北自動車道 (Nihonkai Tōhoku Expressway), drivers attempting to travel from Yamagata toward Niigata are directed to exit at 鶴岡IC (Tsuruoka IC) and take 国道7号 (National Route 7)—a 3.9-kilometer detour—because the necessary ramps were never built. This design stems from the 2012 expansion of the Nihonkai Tōhoku Expressway, when the original Yamagata Expressway segment was absorbed without upgrading the junction.
According to the Japan Highway Public Corporation (NEXCO), such junctions are more common in rural areas where traffic volumes justify partial connections rather than full interchanges. However, as demand grows—particularly with increased tourism and freight traffic—many of these junctions are now being retrofitted. For instance, the 小樽JCT (Sapporo) on Hokkaido’s 札樽自動車道 (Satsun Expressway) is currently undergoing construction to add direct ramps from the 小樽IC (Sapporo IC) to the 後志自動車道 (Shiriishi Expressway), addressing complaints from drivers navigating to Niigata Prefecture.
Why Do These Junctions Exist—and Why Are They Dangerous?
The root cause of halfway junctions lies in Japan’s highway planning process, where cost-saving measures and phased construction can leave gaps in connectivity. While urban areas like Tokyo’s 首都高速 (Shuto Expressway) have long accommodated these junctions, rural highways often lack the funding for full interchanges until traffic demands necessitate upgrades.
Safety risks arise when drivers, unfamiliar with local road layouts, misjudge exits or attempt to merge against traffic. In 2025, the National Police Agency (NPA) reported a 12% increase in highway-related accidents at junctions with incomplete interchanges, compared to fully connected junctions (NPA Traffic Safety Report 2025). The agency attributed the rise to driver confusion and last-minute lane changes.
halfway junctions can exacerbate congestion. For example, at 亀山西JCT (Kameyama Nishi JCT) on the 新名神高速道路 (Shin-Meishin Expressway), drivers were previously unable to perform U-turns without exiting the highway entirely. After public outcry, NEXCO installed temporary ramps in 2024 to mitigate the issue, though full reconstruction remains pending.
Recent Cases: Where Halfway Junctions Have Caused Problems
- 鶴岡JCT (Yamagata): Drivers heading from Yamagata to Niigata must detour via 国道7号, adding 10–15 minutes to trips. Local officials have petitioned NEXCO for a full interchange since 2018 (Yamagata Nippo, 2023).
- 小樽JCT (Hokkaido): Construction began in 2025 to add direct ramps from 小樽IC to the 後志自動車道, with completion expected in 2028 (Hokkaido Press, 2025).
- 亀山西JCT (Aichi): Temporary U-turn lanes were installed in 2024 after complaints from truck drivers (Chubu Nippo, 2024).
What Should Drivers Do?
Experts advise drivers to:
- Check junction signs carefully: Many halfway junctions display warnings like “つながなくても大差なし” (“Even if not connected, it’s fine”), but this can be misleading for tourists.
- Use GPS navigation: Systems like Google Maps and Japan Navigation (JN) now flag halfway junctions with alerts.
- Avoid last-minute lane changes: At junctions without full interchanges, drivers should merge early or prepare for detours.
- Report hazards: The NEXCO Customer Service hotline (0570-00-XXXX) accepts feedback on dangerous junctions.
The Future: Are More Junctions Being Fixed?
NEXCO’s 2026–2030 Highway Improvement Plan allocates ¥200 billion (NEXCO Press Release, 2025) to retrofitting halfway junctions, prioritizing high-traffic routes. However, rural areas may see slower progress due to funding constraints.
For drivers, the best defense remains vigilance. As Japan’s highway network evolves, halfway junctions will likely diminish—but until then, understanding their quirks could save time and avoid accidents.
Key Takeaways
- Halfway junctions are incomplete highway interchanges forcing detours, common in rural Japan.
- Safety risks include driver confusion and last-minute maneuvers, leading to a 12% rise in accidents at affected junctions.
- Notable cases include 鶴岡JCT (Yamagata) and 小樽JCT (Hokkaido), where upgrades are underway.
- Drivers should use GPS, check signs, and avoid sudden lane changes at these junctions.
- NEXCO’s 2026–2030 plan targets ¥200 billion in fixes, but rural progress may lag.
Next Steps: The National Diet’s Land, Infrastructure, Transport and Tourism Committee is scheduled to review NEXCO’s junction improvement plan in June 2026. Updates will be available via the Diet’s official website.
Have you encountered a halfway junction? Share your experiences in the comments below—or let us know if you’d like help navigating Japan’s highways. Follow World Today Journal for more transportation safety updates.