The "tunnel effect" is a geographical phenomenon where improved transportation infrastructure, such as highways and high-speed rail, can unintentionally harm the local economy and population of rural areas. This happens when faster transport routes allow people to bypass local shops and services, leading to their decline and the depopulation of villages. The term was coined by geographers Camille Tiano and Clara Loïzzo, who describe it as the removal of local "relay points" — small towns or villages that once served as intermediate stops — by the introduction of fast transport systems that bypass these areas. This can leave rural communities isolated and economically weakened. In France, this issue has been a concern for over sixty years. The government established the Délégation à l'aménagement du territoire et à l'action régionale (DATAR) in 1963 to address regional imbalances and promote balanced development. DATAR aimed to redistribute populations, create new economic zones, and modernize infrastructure. However, the focus on connectivity often led to unintended consequences, as high-speed transport systems, such as trains and highways, were built with fewer access points to optimize speed and efficiency. This left many rural areas disconnected from the new infrastructure, with no easy way for residents to reach or use the roads and railways. Examples of the tunnel effect are evident across France. The Haute-Picardie TGV station, located between Amiens and Saint-Quentin, is nicknamed the "beetroot station" because it is seen as disconnected from the surrounding rural life. Similarly, the A31 highway crosses the Langres plateau without any public access points for 32 kilometers, despite seventeen roads crossing it. This disconnect means that many people in nearby villages cannot easily access the highway, even though it passes near them. In smaller villages, the effect can be just as significant: residents may choose to travel to a larger town for shopping, reducing local commerce and contributing to the gradual emptying of rural areas. The ongoing closure of shops and services in rural France has significant social and economic consequences. Each loss of a local business reduces the appeal of the village center, accelerating the cycle of decline. The original goal of planners — to connect and develop rural areas — often ends up having the opposite effect. Some senators have criticized the simplistic criteria used to measure disconnection, arguing that they fail to capture the complexity of rural dynamics. In response, geographers and planners are calling for a more comprehensive approach, one that considers local consumption patterns and supports small businesses when new transport routes are built. Some local authorities have started tying financial aid to commitments to preserve local commerce, recognizing that roads and highways alone cannot sustain a village. A recent example of the risks of over-reliance on connectivity occurred in Cap Sizun, a coastal village in Finistère, where a bridge collapsed during winter storms, cutting off access between two communes for several months. The sudden isolation highlighted how dependent local communities had become on continuous connectivity. The disruption led to renewed challenges for local businesses, as residents who were used to easy access found themselves cut off. Geographers continue to study the balance between connectivity and local identity, searching for a way to build infrastructure that links communities without making them forget the places they cross.