CHOIX DE VARIANTE DANS LA TRAVERSEE DE LA VILLE DE KALFOU (REGION DE TAHOUA, NIGER):CONFORMITE GEOMETRIQUE, IMPACTS FONCIERS ET STRUCTURE SOCIALE DE L'ACCEPTABILITE

Selecting road alignment through a built-up area places normative requirements, earthwork constraints and localised land interests in tension. This article compares two alignments for the crossing of Kalfou, on the Tamaske-Tahoua axis in Niger: the one specified in the 2020 tender documents (variant A) and an alternative derived from GNSS surveys by the authors (variant B). The comparison draws on compliance with T80 geometric standards, an adversarial census of affected assets, and a consultation of 101 stakeholders; twenty-eight indicators are aggregated by simple additive weighting, with weights derived from stated preferences. Variant A includes a horizontal radius of 100 m, below the minimum of every category in the applicable standard and requires 142,659 m3 of excavation affecting three water towers, sixteen electricity poles, over 300 m of water mains and 941 m2 of cemetery. Variant B corrects this non-compliance and cuts earthworks by 71.8 % but affects 61 rights-holders against 45 and moves the road away from the health centre and the chieftaincy, from 20 m to about 500 m. Aggregation selects variant B with a relative margin of 17.9 %, a ranking that withstands all nine weighting vectors tested, including those derived from residents alone.