Achieving the target California Bearing Ratio (CBR) value for the topmost layer of natural earth. Series 4000: Granular and Stabilized Bases

The 2000 specification is a snapshot of priorities: durability over short-term cost savings, clarity in measurement to reduce disputes, and prescriptive tests intended to fend off local variations in practice. It also hints at constraints—limited laboratory capacity in some regions, the reality of rainy and dry seasons that define construction windows, and the economic imperative to favor locally sourced materials.

Establishes contractor obligations for safety and environmental protection.

Single or double-seal chip seals using targeted aggregate sizes and hot bitumen sprayers.

: Guidelines for cutting and filling to achieve the desired subgrade level.

Mandatory protocols for temporary diversions, signage, and safety flagmen to protect the public and site workers. Series 2000: Drainage Structures

Adds erosion control, borrow pit rehabilitation, and dust suppression requirements not detailed in the 2000 version.