Impacts of Informal Activities, Particularly on-Street Trading and Illegal Parking, on Carriageway Capacity and Overall Traffic Efficiency: Ogunnusi Road, Ojodu Berger, Lagos Corridor Study

Abstract

This study investigates the multi-dimensional determinants of traffic congestion along Ogunnusi Road (Ojodu Berger, Lagos), with particular emphasis on quantifying how informal activities, specifically unregulated on-street trading and illegal or double-parking, erode effective carriageway capacity and undermine overall traffic efficiency. The research adopts a mixed-method descriptive and explanatory design, drawing on structured stakeholder questionnaires, manual traffic volume counts, travel-time/delay surveys, lane-width measurements, GPS-based vehicle tracking, and semi-structured interviews, complemented by geospatial analysis in QGIS for hotspot buffer mapping and bottleneck identification. A stakeholder sample of 156 respondents, scientifically determined using the Taro Yamane formula, was stratified across traders, commuters, logistics operators, policy officials, and traffic enforcement personnel, while secondary data were synthesised from international traffic engineering frameworks and local transit publications. Data were evaluated using descriptive and inferential statistics, including Chi-square (X²) testing, to validate the study's hypotheses. The empirical findings confirm that the corridor operates at Level of Service (LOS) F during peak periods, with severe degradation directly attributable to a substantial reduction in effective carriageway width caused by unregulated on-street trading and persistent illegal or double-parking on feeder routes such as Kosoko Street. To reverse this degradation, the study proposes a phased mitigation strategy spanning immediate regulatory action and long-term infrastructural investment. In the short term, enforcement of clear-zone corridors along Ogunnusi and Kosoko Roads, sustained through continuous traffic-enforcement patrols, should eliminate on-street trading and unauthorised curbside or double-parking; rather than relying on punitive eviction alone. This should be paired with the socio-economic formalisation of affected traders into designated off-street vending pods, an approach observed to improve urban traffic flow by up to 46% in comparable regional contexts while preserving trader livelihoods. A geometric intervention — construction of a median cut at the Ogunnusi Road/Kosoko Street intersection, supported by signalised traffic-light control is recommended to permit left-turning movements from Kosoko Street directly toward the Lagos–Ibadan Expressway, thereby easing congestion around the Road Safety office and shortening travel times without requiring vehicles to pass by it. In the long term, the study recommends a jointly funded Lagos–Ogun State arterial bypass linking Lambe or Akute directly to the Lagos–Ibadan Expressway, structured as a self-financing public–private partnership (PPP) with toll-based cost recovery to divert peripheral-ward traffic away from Ojodu Berger, alongside the development of organised Park-and-Ride facilities at Agbado, Lambe, and Akute to reduce private-vehicle reliance and lower peak-hour vehicle-kilometres-travelled (VKT) along the primary corridor. Institutionally, implementation should be anchored by the Traffic Unit of the Ministry of Transportation in formal collaboration with Local Council Development Areas, law enforcement agencies, and community development groups, with enforcement personnel deployment expanded in line with international urban traffic standards