我が国の自転車事故は交差点で発生する割合が高く,しかも,自動車の挙動によって衝突する自転車の進行方向に偏りが見られ,世界的に希な双方向通行の常態化が安全性の課題と考えられる.歩道での双方向通行が認められていることから,車道部でも左側通行を遵守しない自転車が多く,通行空間が確保された自転車レーンを逆走する自転車も見られる.本研究では,逆走自転車を自転車センサで感知してLED文字表示板を点灯させることにより警告を行う装置を開発し,徳島市内で整備された自転車レーンにおいて社会実験を実施した.パネルによる立会警告に比べると高いとは言えないものの,逆走自転車の低減に一定の効果は見られており,装置改善,安価化により補助的装置として活用が可能と考えられる.The ration of bicycles accidents at junctions is quite high in Japan, and the crash direction of bicycles is biased depends on the vehicles’ behaiviors. The regularization that bicycles run in both direction on most of streets in Japan, which is rare system in the world, should be considered for the reason of this phenomena In Japan, because both way cycling is permitted on sidewalk, wrong way cycling on not only roadways but also bicycle lanes. The aim of study is to develop an on-street warning device that can sense wrong way running bicycle and warn them by flushing character LED display. By employing the experiments on a street with bicycle lane in Tokushima City, the effects of this device is tested comparing with the personal guidance on street using warning panels. As results, certain effects by the device was found so that the developed device has the possibility of auxiliary warning method for the reduction of wrong way cycling