The road construction is carried out by a contractor as per design specifications as contained in the tender. All projects have a Resident Engineer (RE) who is meant to ascertain that works are executed as per specifications. The RE endorses all Completion Certificates that forms the basis for payment by the client (KenHA, KURA, KERRA etc). If works are poorly done, I would blame the RE more than the contractor.
Where the design has issues like the Chiromo Road junction(Museum Hill) the two parties needed to have agreed in the on site design changes.
"..I am because we are. "― Ubuntu, Umtu,