Effects of Congestion and Travel Time Variability along Abuja - Keffi Corridor in Nigeria. Global Journals of Research in Engineering, [S. l.], v. 12, n. E3, p. 19–26, 2012. Disponível em: https://testing.engineeringresearch.org/index.php/GJRE/article/view/584. Acesso em: 6 jun. 2026.