A Perception-Based Walkability Index for an Informal-Economy CBD Corridor: Kenneth Matiba Road, Nairobi

Abstract

Pedestrians account for most road traffic fatalities in Sub-Saharan Africa, yet walkability frameworks developed in high-income countries do not capture the contested streetscape of informal-economy Central Business Districts or the systematic attribution biases between road users. This study develops and validates a perception-based Walkability Performance Index (WPI) using survey data from 1,248 respondents (614 pedestrians, 425 drivers including 218 matatu operators, and 209 vendors) along Kenneth Matiba Road, a 250-metre Central Business District corridor in Nairobi. The corridor scored 39.0/100, with infrastructure adequacy the weakest sub-dimension (32.4/100). A 1.57-point attribution asymmetry on driver yielding was documented (rank-biserial r = 0.68), with significant matatu–private differences. Pedestrians and vendors converged on designated vending areas as a priority intervention. The instrument showed strong reliability (Cronbach’s α = 0.870) and offers a low-cost diagnostic for Central Business District corridors across Sub-Saharan Africa.