Petrol-Retail Market Structure and Corridor Competition in Keffi, Nigeria: Evidence from a Geocoded Outlet Inventory

The spatial distribution of petrol retailing influences accessibility, rivalry, corridor extension, and cumulative urban motor road burden. This paper investigates the operational structure and corridor level rivalry of filling stations in Keffi Local Government Area, Nigeria. It complements previous papers on the aggregated spatial pattern of stations, planning compliance and stakeholder-emergency management perceptions of market accessibility and public-safety risks. It builds upon the parent thesis‟ geocoded census of 43 active and inactive outlets in 2025 down to eight road corridors. Subsequently, operator names were cleaned and standardised, and outlet shares, CR4, HHI and corridor level operator diversity were derived. The parent census revealed 31 operator identities, of which 25 (80.6%) appeared once, with 58.1% of outlets (N=40) attributed. Abzat and NNPC each operated four stations, while MRS and Munsir each operated three. The four largest entities held 32.6% of outlets. The system-wide HHI of 449 (on a scale 0-10,000) indicated a fragmented pattern of ownership traditionally characterised as monopoly. Geographically, rivalry was highly concentrated: 60.5% of outlets were evenly distributed among the Abuja-Keffi, Keffi-Akwanga and Nasarawa Bypass corridors, with the remaining two minor corridors each hosting one outlet. Although between corridor operator competition was average to high, corridor level operator diversity was generally high, implying that non-monopoly spatial clustering resulted from attraction to traffic and navigational exits. The paper concludes that relative low ownership concentration can coexist with extreme locational concentration; hence licensing decisions should measure both. A continuously updated store-locator register, verification of outlet state, corridor saturation indices, and integration of traffic, price, throughput, and service area data is recommended.