What is one of the reasons the Engineer may restrict the use of vibratory rollers?

The reason the Engineer may restrict the use of vibratory rollers is primarily to protect the pavement structure. Vibratory rollers deliver significant compaction forces through their vibration mechanism, which can be beneficial in many applications. However, if used inappropriately, they can also lead to excessive compaction, leading to potential damage to the underlying pavement layers or the pavement itself.

In cases where the materials in the subgrade or pavement structure are sensitive to vibration, using vibratory rollers can create detrimental effects, such as cracking, deformation, or even instability. The Engineer's responsibility includes ensuring the long-term durability and performance of the roadway, which necessitates a careful assessment of what equipment is appropriate under given conditions. Thus, the decision to restrict vibratory rollers is aligned with protecting the integrity of the pavement structure and ensuring a sound foundation for the road surface.