Influence of parking on congestion of Nairobi central business area

Abstract

In Nairobi central eree, traffic qenerelly flow's under congested conditions. Generally, traffic congestion has nega.tive effects on operations of town centers, Nairobi centredarea included. Commercial and business life of Nairobi central area just like any other town centre, usually requires to be served by motor traffic. Traffic congestion impedes operations and efficiency' of vehicles involved in business and commercial activity'. For example, travel time and fuel are lost while vehicles' enqines are running at stationery jam situations caused by traffic congestion. Thus, traffic congestion norrnelly impairs business efficiency in hlairobi central area. Parking is one factor that causes 1\IBjrabi central area's traffic congestion problem. However. information is lacking as to the extend to which parked vehicles contribute to the traffic conqestion problem. This study's eirn is to find out this rnissing intormetion. by carrying out surveys of traffic stream characteristics in the area and analyzing the data. Surveys carried out are traffic flow counts, travel time and parking usage surveys. Data obtained from the survey's 'Nas stored and enelysad by a computer using packages that were readily available. These pe.cke.ges \lvere Vv'ord Perfect 5.1, Lotus 123. Harvard Graphics, qrepher end Ste.tgmphics . Analysis of the data established that: • Plots of variation of traffic speed with flow were typical speed flow CUNes. o For 52% of the study period, dernend for on-street parking space exeeded it's supply. The extra demand was catered for by illegal and double parking. Consequently, there were reductions in cerriaqewey widths eveilebls for moving traffic, reductions in vehicle overtaking opportunities, reductions in tre.fficspeeds and ultimately. traffic congestion. • Traffic congestion existed in the eree, as evidenced by traffic speeds that were below critical speeds (established by speed flow curves).