By Frank Kweronda
The increase in urban traffic congestion has become a serious concern in Kampala City. As Uganda grows economically, with proper utilisation of resources such as hydropower and oil, there is need to improve infrastructure.
However, improvement starts with Kampala City which is congested and lacks perfect roads, planned buildings, proper drainage and sanitation.
In order to ease transportation problems in Kampala City, the urban authority should take up an initiative for construction of flyovers at major intersections. Road flyovers are an essential feature of urban road development initiatives the world over.
These have also been resorted to extensively on the highways for ‘grade separation’, that is avoidance of crossings at the same level. In advanced countries, multi-level flyovers are also resorted to, allowing uninterrupted criss-cross movements of traffic in different directions.
A flyover is a bridge that carries one road or railway line above another either with or without subsidiary roads, for communication between the two. Reason behind going for a flyover is that as the traffic on the road goes on increasing and we don’t have any space left in both the dimensions, then the only option left will be to go to the third dimension and that is done through flyover construction.
One of the types of flyovers which are used for traffic management at road crossings are simple flyovers: - In this case, the main road is used for fast traffic, which is made to pass at a high level by a bridge, providing ramps on both the approaches; and the slow traffic is made to pass underneath.
Thus the traffics pass at two different levels, and leave no chance for an accident.
Even after providing the flyover, as we have to continue providing the traffic lights at the intersection beneath the flyover so as to make a person approaching from any direction reach every other direction, the flyover is not replacing the traffic lights. Railway Crossing: - At railway crossing where there is high traffic congestion in terms of the frequency of the traffic on the road or trains passing by, in both the cases the flyover should be provided along the road. Here the flyover becomes indispensable.
Advantages of flyover are that they play a major role in streamlining the traffic control system. Through flyovers, plenty of time is saved avoiding congestion.
Pollution effect is reduced; risk of accidents is reduced, saves motorists and commuters’ time as well as fuel and also contributes a lot to the aesthetics of the city.
Road flyovers have an added advantage of helping to create additional road space overhead, minimising the acquisition of built-up lands on either side, which is costly and time-consuming, besides causing great hardship to those affected. The persons traveling on the flyover can enjoy the panoramic view of the city.
All roads, flyovers, etc are designed solely to accommodate the heaviest and tallest vehicle: the fully loaded truck, thus resulting in a gross over design for cars. The slab of a flyover is designed to withstand the 20 tonne weight, (dynamic load) of a fully loaded truck.
After discussing the various facts what we can say is that flyovers should be constructed only if the benefits from it are far greater than the cost incurred.
Also proper location must be decided in constructing it with proper management. It should be seen that as far as possible the flyovers purpose is consummated.
Prefeasibility studies could be made by engaging our own experts so that this is considered as an option for the very near future by adopting a comprehensive planning approach.
The writer is a civil engineer