八木山峠：国道201号線八木山バイパス編 篠栗町～飯塚市　福岡～筑豊間の大動脈　再有料化と一部4車線化　2025年7月見学

[Mountain Pass Scenery] National Route 201 Yagiyama Bypass Edition, Visited in July 2025 [Yagiyama Pass] Yagiyama Pass is a pass on the Sasaguri Kaido, connecting Fukuoka and Iizuka, that crosses the Mikuni Mountains. Its name seems to have been derived from the fact that it passes through the basin where the Yagiyama settlement is located along the way. The transportation routes between Fukuoka and Iizuka were the Sasaguri Kaido in premodern times, and now National Route 201, National Route 201 Yagiyama Bypass, and JR Kyushu Sasaguri Line. Of these, only the Sasaguri Kaido and National Route 201 pass through the Yagiyama Basin, while the National Route 201 Yagiyama Bypass and JR Kyushu Sasaguri Line bypass the area to the south. Neither the National Route 201 Yagiyama Bypass nor the JR Kyushu Sasaguri Line passes through Yagiyama Pass itself, but since they are both mountain pass routes between Fukuoka and Iizuka, we will treat it as Yagiyama Pass. [About the Yagiyama Bypass] National Route 201 Yagiyama Bypass is a 13.3 km expressway stretching from Sasaguri Interchange in Sasaguri Town, Fukuoka Prefecture, to Honami Higashi Interchange in Iizuka City, Fukuoka Prefecture. It opened as a temporary two-lane toll road on February 26, 1985. The longitudinal section features a standard mountain pass crossing, with a continuous 4.6% uphill gradient for approximately 4 km between Sasaguri Interchange and Chikuho Tunnel, and a continuous 4.4% to 5.0% downhill gradient for approximately 5 km between Chikuho Interchange and Honami Nishi Interchange. It was opened as an alternative route to overcome the hurdles of Yagiyama Pass on the previous route of National Route 201. However, with the economic development of the Fukuoka metropolitan area and the increase in freight volume, and the toll road becoming toll-free in 2014, traffic has become concentrated on the Yagiyama Bypass. The Fukuoka East Bypass and Iizuka-Shonaidagawa Bypass, which connect to the Yagiyama Bypass and were opened later, are four-lane roads, making the two-lane Yagiyama Bypass a bottleneck, resulting in congestion and accidents. As a result, construction work to widen the road to four lanes began in April 2020, with the section between Sasaguri IC and Chikuho IC being widened to four lanes from March 30, 2025. The section between Chikuho IC and Honami Higashi IC is scheduled to be widened to four lanes by fiscal year 2029. To secure funding for the four-lane expansion, tolls will be reinstated, and the toll booth we just passed has been re-installed at the location we just passed. The Yagiyama Bypass was opened as a detour around the south side of National Route 201 to eliminate the traffic bottleneck at Yagiyama Pass. While it's significantly easier to drive than the Yagiyama Pass route, it still remains a challenging mountain pass road, with a continuous gradient of approximately 5% for about 4-5 km. The section between Sasaguri IC and Chikuho IC will be widened to four lanes from March 30, 2025, and construction is currently underway on the remaining sections. The four-lane expansion will help stabilize traffic and is expected to have a significant effect even if tolls are introduced, making a significant contribution to smoother traffic flow along Fukuoka Prefecture's east-west axis. 00:00 Prologue 01:38 Yagiyama Pass 02:32 Sasaguri IC to Chikuho Tunnel 09:01 Chikuho Tunnel: National Route 201 Yagiyama Bypass 10:35 Chikuho Tunnel to Honami Nishi IC 15:45 Epilogue Related Videos ・Yagiyama Pass: Sasaguri Line Edition, Sasaguri to Katsuragawa River, November 2023 　   • 八木山峠：篠栗線編 篠栗～桂川　福岡地域と飯塚地域を隔てる三郡山地を横断する八木山峠...   ・Yagiyama Pass: National Route 201 Edition, Sasaguri Town to Yagiyama to Iizuka City, November 2023 　   • 八木山峠：国道201号線編 篠栗町～八木山～飯塚市　福岡地域と飯塚地域を隔てる三郡山...   ・Yagiyama Pass: National Route 201 Yagiyama Bypass Edition, Sasaguri Town to Iizuka City Visited in November 2023    • 八木山峠：国道201号線八木山バイパス編 篠栗町～飯塚市　福岡～筑豊間の大動脈はただ...   ・Yagiyama Pass: Prefectural Road Edition, Sasaguri Town to Iizuka City. Visited in November 2023. Not yet ・Yagiyama Pass: National Route 201 Yagiyama Bypass Edition, Sasaguri Town to Iizuka City. Toll roads will be reinstated and some roads will be expanded to four lanes. Visited in July 2025. Here BGM: Official Sharou Song Title/Composition 1) Hidamaritronica / Sharou 2) Morning / Sharou 3) You and Me / Sharou 4) Far East Sheep Dancing with a Telecaster / Sharou 5) The Stray Cat Aims for Space / Sharou