The decision to construct the motorway was taken based on the report of the British railway engineers concluding that the mauritian railway lines would have cost Rs 35 millions to be modernised in addition to a yearly loss of Rs 4 millions for its maintenance.
In 1955, after certain discussions with the Colonial Office, the Government decided to construct a new road, the motorway. It was requested from the global firm ‘Sir Alexander Gibbs & Partners’ to examine the technical possibilities of such a project. In 1958, after having examined the propositions of the said firm, the Government requested the latter to establish the road map with the traced span. The contract was given to the firm ‘A.C Burton & Co.’ at the agreed total amount of Rs 8 millions, out of which one third (1/3) was to be paid by the Mauritian Government and the remaining two thirds (2/3) by the British Government.
In 1960, Burton & Co started the works for the motorway from Phoenix to Port Louis (Bell Village) and this distance of 12.5 Km was designated to be of dual lane over a width of 24 feet for each of the two carriage ways. The safe riding speed was established at 100 KM/H given that nowhere on this traced route was safer for a speed above that specified, with the visibility being an important factor of consideration.
This new road had to cross 15 rivers (including irrigation canals) which necessitated the construction of 7 aqueducs and 8 bridges, with the largest and longest being at Sorreze/Mont Ory, the Coleville Deverell bridge. This bridge took 11 months to be completed and employed the pre-stressed concrete method, a first in Mauritius.
In addition to the bridge, new methods of road tarring had to be used given that the availability of gravels was a problem. Special machinery mixed up soil, lime and water which became very solid and this was laid as the base. Afterwards small rocks (1/6 – 3 inches) were compressed onto the base and this was followed by a new asphalting technique of mixing concrete, sand and rocks at high temperature to make a smooth and levelled road.
Unfortunately this was only the first part of the motorway, from Phoenix to Port Louis. The second part from Port Louis to Pamplemousses was executed 20 years later, around the 1980s.