Effects of Road Improvement on Safety:A Case study of Nairobi – Thika Superhighway, Kenya

Abstract

Road safety is one of the main transportation problems in developing countries. The major goal of the transportation system is to enhance mobility and road traffic accidents (RTA) are unwanted by-products which have to be minimized while achieving the primary goal. 45km Nairobi – Thika Superhighway Improvement project was inaugurated on December 2009 and completed in November 2012. The project involved redesigns of all intersections and increment in the road lanes to enhance capacity and improve safety. The research aimed to review the crashes occurrences on the improved highway in three phases; before, during and after construction. This research sought to assess the role of incorporation of different safety measures in road projects in Kenya and improve public awareness on the use of road safety provisions with the aim of reducing road traffic accidents and subsequently casualties. The approach used to realize this study involved gathering data from traffic police stations, conducting interviews to get the opinions of road users on safety and making observations on the turning movements of vehicles and pedestrians. The interactions were explored, analysed and modelled using Chi-squared distribution. These were then used to identify accident black spots and assess the effectiveness of road safety measures installed in the new Nairobi Thika superhighway. The total number of accidents recorded over the eight-year period was 993.This study revealed that most accidents occurred before and at the start of reconstruction, reduced by 55% during construction and increased by 79% after completion. 39% of these accidents were fatal, 41% were severe and 20% were slight. Most accidents occurred in the months of July and August. It was observed that the main types of accidents on the highway are Vehicle-Pedestrian; those involving motorcycles were fewer. The highest number of accidents recorded was at Githurai 45, followed by Safari Park and General Service Unit (G.S.U) zones and the least was at Clay works area. Small cars had the highest number of fatal, serious and slight accidents followed by public service vehicles. Most accidents occurred between 1930 and 2030 hours. Drivers and pedestrians were found to be contented with the facilities installed for their safety despite the deficiency in number provided and their locations. The most efficient road safety facilities were found to be footpaths and foot bridges. It is recommended that road safety audits be done on all our roads and retraining offending drivers and all PSV drivers to emphasize change of behaviour and safe driving.