Performance adequacy of intersections with regard to non-motorized traffic (NMT) needs in Dar es Slaam

The provision of non-motorized transport (NMT) facilities has not been emphasized in Dar es Salaam city roads, as is elsewhere in developing countries. Priority has been given to motorized traffic (MT) so compromising the mobility and safety needs of NMT. The most critical and complex elements in highway design and operation to be considered are the intersect5ions. It is at the intersections where majority of MT and NMT conflicts occur and hence, delays and all other negative roadway impacts are prevalent. In urban and suburban areas in particular, the performance of intersections can effectively define the performance of the highway system. This study investigated the performance adequacy of nine at-grade intersections in DSM on the NMT needs. This included: Four –Signal Controlled; Four’-Priority Controlled; and ‘One’ Roundabout Intersections. Literature review of the intersection design standards and performance requirements for NMT has been done. The study also involved field work in which data inherent to the intersections were collected. These include: traffic volume and composition, speed, geometric features, control & operational features, and other intersection deficiencies. Data analysis were conducted by employing state-of-the-art modus operandi, by computing LOS using Multimodal ‘Point’ LOS methodology. Results were compared with corresponding ‘Point’ LOS criteria, and reveal that all of the intersections investigated operate either in LOS E or F- NMT flow is under unacceptable worst movement conditions in terms of comfort and safety. The study recommends how to improve this to a desirable condition and also the way forward.