Unscheduled repair of locations with potential risks of falling rocks and traffic safety at sections Km118+660-Km118+783(T); Km120+765-Km120+850(T); Km127+963-Km128+219(P); Km128+672.65-Km128+864(P); Km138+437-Km138+583 (W)/National Highway 6, Hoa Binh province