What angle should the shoulder wedge be constructed at, according to the contract specifications?

The specification for the shoulder wedge angle of 30 degrees, with an allowed tolerance of plus or minus 4 degrees, is important for ensuring proper drainage and structural integrity of the roadway. A shoulder wedge that is well within this angle helps to manage water runoff effectively, reducing erosion and maintaining the stability of the road and shoulder.

Using this specific angle range ensures that the slope is appropriate for supporting adjacent materials and facilitating vehicular movement. It is crucial that the angle is adhered to closely, as variations beyond the specified tolerance could lead to issues with drainage, structural performance, or increased maintenance needs.

Understanding the rationale behind using a specific angle and its tolerances helps in maintaining the overall quality and safety standards specified in the contract.