Building Of lnterchanges Is Professional Failure of Ghanaian Engineers & Architects

I had already written to sensitize and conscientize Ghanaian society, especially those in the officialdom of the concept and the function of interchanges and l will continue until it is completely drummed into doltish ears of the powers that be

Now, interchange, the one, Kwame Nkrumah Circle has changed to or what Tetteh Quashie roundabout is now known, is built or designed from technical point of view to connect motorways to conventional roads and motorways to motorways, nothing short of that

Except, footbridges, bridges, elevated level-crossing (bridges for railway tracks), interchanges are mainly outskirt of the urban areas built on motorways to fullfil special function

The function of interchange/s is to make sure

1. The circulation of vehicles using motorways is not unduly altered by those using conventional roads which cross the motorways
2. Circulation within motorways is not unduly altered by the vehicles themselves as the motorway diverts into several motorways at a point
3. To act as entrance and exit points of motorways

The above is the function and concept of interchange/s. In other words, Kwame Nkrumah interchange is competely unnecessary. Interchange is not meant for urban areas(city centers) or conventional roads, and or, to conventional roads

Awoshie-Pokuase road - though l haven't seen that part of the components of major roads within and outskirt of Accra, the capital of Ghana for more than four years, l can deduce that - is not a motorway. Hence government's decision to build Awoshie-Pokuase interchange is completely waste of money

Awoshie-Pokuase road is what l call as "conventional roads," that is, Awoshie-Pokuase road is not motorway, nor a point where motorway and conventional meet, neither is a point where several motorways meet hence there is no need for interchange. What Awoshie-Pokuase junction needs is big roundabout well painted and prominently displaced road signs and traffic lights, and in worst scenario, with traffic police

What makes motorways different from what l call conventional roads: In Spain, we have two types of motorways, with tollbooth and the one without tollbooth. The one without tollbooth is mainly double carriage roads, mostly inter-city with two lanes in one direction and other two in the opposite direction. While the one with tollbooth has more than two lanes in one direction and more than two lanes in opposite directions

Motorways unlike conventional roads are special in the sense that they are completely fenced, in other European countries like France and Germany, even if they aren't fenced, the edges are protected in the manner that property owners (farmlands, factories) adjacent to it can't enter their properties from the motorways. That is, they have to do it through conventional roads

Motorways, mostly with blue-background road signs, have strictly enforced mininum speed limit of 60 kms/h. They have maxinum speed limit of averagely 120kms/h - though, passively tolerated up to 160kms/h

If for whatever reason a motorway user runs less than 60 kilometers per hour, then it has to abandon the motorway by the next exit (interchange)

Motorways unlike conventional roads, scooters, cyclists, pedestrians, agricultural machinaries; tractors, harvesters, animal-hauled vehicles are completely prohibited

To get the picture why interchanges are the imperative connecting point of motorways and conventional roads; interchanges comes with additional incorporating high and low velocity lanes(the so-called '3tier')

In that, a road user doesn't have to slow or reduce the velocity in the motorway. The driver has to reduce the velocity of the vehicle in the low-velocity incorporating lane that comes with interchange while using high velocity extra incorporating lane to get the "adequate" or maximum velocity to blend in the motorway........To be continued