Based on the latest United Nations estimates, as per October 21st 2018, the population of Kenya stands at 51.3 million. This shows an annual growth of around 2.5% every year. The approximate population of Nairobi is around 6.5 million in the metropolitan area and 3.5 million in the city proper as per 2009.The Ongata Rongai population has increased from 40178 in 2009 to approximately 66042 in 2018.The increasing population is due to the rapid urbanization. However, the increase in population has consequently led to an increase in traffic congestion in the area Magadi Road links Ongata Rongai to Lang’ata and Karen and further into Nairobi CBD. Due to the relatively cheap housing compared to other Nairobi outskirts, majority of people working in Nairobi reside in Ongata Rongai. In addition to that, following the unfortunate events of the 2008 post-election violence in the country, majority of people migrated to Ongata Rongai. The sudden surge of population in the area was not properly planned for. With increasing population comes increase in demand of the social amenities and infrastructure such as hospitals, supermarkets, schools and roads. The demand therefore surpassed the supply in terms of road infrastructure hence creating the problem of traffic congestion.
Magadi road has been highly affected with traffic congestion over the years. Residents of Ongata Rongai have complained of the consistent traffic jams occurring from Monday to Monday. The complaints have been further propagated by occurrence of traffic jams during weekends and public holidays, when it is theoretically expected for flow to be uninterrupted. Besides that, during a normal working day, one is expected to leave the town at around 5am in order to reach Nairobi CBD at around 6am.Leaving at around 6 am results in one reaching Nairobi CBD at around 9am.This journey, if uninterrupted, takes around 15 minutes. This is the same case as in the evening hence rendering movement from Ongata Rongai to Nairobi to be highly stressful and time-consuming. (Mwangi ,2014; Achuka, 2015). Consequently, the economy of the country is affectedas man-hours are wasted, fuel consumption in the traffic jams is high and also there is increased environmental pollution.
It is therefore evident that my project study is carried out in order to assess all the possible causes
of congestion on the road. In addition to this, the capacity of the road will be studied to determine
its suitability in handling the increasing demand thus defining the traffic index of the road. The
traffic index is the composite index of time consumed in traffic while commuting to work, road
user dissatisfaction, carbon (IV)oxide- emission estimation in traffic and overall inefficiencies in
the traffic system (Mutavi,2017)