Actually its no that easy.Kenya needs major financing to make the over 1000KMs road a four lane highway.Assuming that all they do is just add extra lane on both sides the cost would easily be about 4 billion per 50kms.But this is not practical since it is a recipe for disaster.A divider needs to be erected.but a 1000 km divider?also not practical.So the only option would be to build an extra road which is a few meters away from the original road.they would also need to build a few interchanges for all some of the transit towns in between.
added to cost of resettling displaced businesses,people,moving poles,water systems etc,and the cost of just building 50 km could easily reach 7-10 billion kshs. So we are talking of over 100 billion kshs on a single road project.kenya's overall infrastructure budget(all roads,bridges,energy etc) for 2010 was 220 billion kshs,this means we would have spent half of it building a single road.
Don't get me wrong,ofcourse i would love to have the mombasa-busia road as a dual carriageway,but unless Kenya gets funding for it,we simply can't afford it.What we can do is built it in portions until w get the required funding.The government can start with making Busia-Kisumu a dual carriageway,to facilitate easier movement of goods into and out of the country into Uganda.then a dual carriageway bypass in kisumu to avoid going into town.
Other options include seeking BOT (build own transfer) arrangements.Let private companies build the road network and charge tolls to recover their money.
We are lucky we got funding for Thika road from the ADB(african development bank), and maybe in future,if kenya's credit score improves,we move up the ladder in corruption index and remain peaceful,we might just float a 200 Billion kshs infrastructure bond for such projects.