Once upon a time there was a country where vehicles drove on the left hand side of the highway, whereas all the surrounding countries the vehicles drove on the right.
For many good reasons (safety when crossing borders and the extra costs of vehicles with steering wheels on the right of the passenger compartment ) the good politicians of this country decided to adopt the driving practices of the rest of the continent and start driving on the right hand side of the highway.
They immediately recognized their shortcomings in planning and executing such a strategy, so they called in consultants.
After several years of planning and readying the country for the change-over, all was ready. The politicians accepted all the recommendations of the consultants except one-it was decided that given the enormity of the change, affecting as it did not only all the population of the country but also visitors from other countries, rather than having what the consultants referred to as a “big bang” approach they would adopt a less risky “phased approach.”
In the first week only heavy trucks and emergency services would drive on the right, followed by other commercial vehicles in the second week, private cars and trucks in the third week and finally cyclists in the fourth week.