where can i find materials showing how to develop unit rates/prices for road construction activities?
a book or ebook showing the development of BOQ rates from first principles: showing materials, equipment, labour and other cost items (quanities and thencost)

The Richardson Estimating Manual has the specs (capacity, reach, thoughput) of all manner of construction equipment. You multiple by your volumes and distances involved, then check for local rates for equipment and operator rates.
htttp://www.rsmeans.com/